JP7225794B2 - Liquid ejecting head and liquid ejecting apparatus - Google Patents

Description

The present invention relates to a liquid ejecting head and a liquid ejecting apparatus that eject liquid from nozzles, and more particularly to an ink jet recording head and an ink jet recording apparatus that eject ink as liquid.

2. Description of the Related Art As a liquid ejecting head that ejects liquid, an ink jet recording head that performs printing by ejecting ink as liquid onto a print medium is known.

The ink jet recording head consists of individual channels having pressure chambers communicating with nozzles, a common liquid chamber communicating with multiple individual channels in common, and an energy source such as a piezoelectric actuator that causes pressure changes in the ink in the pressure chambers. and an energy generating element that causes a pressure change in the ink in the pressure chamber, thereby ejecting an ink droplet from the nozzle.

In such an ink jet recording head, if air bubbles remain in the pressure chambers, the air bubbles absorb the pressure changes caused by the energy generating elements, making it impossible to normally eject ink droplets from the nozzles.

For this reason, a first common liquid chamber and a second common liquid chamber are provided as common liquid chambers common to the individual flow paths, and ink flows from the first common liquid chamber through the individual flow paths to the second common liquid chamber. An ink jet recording head having a circulating configuration has been proposed (see, for example, Japanese Laid-Open Patent Publication No. 2002-100003).

JP 2012-143948 A

However, there is a problem in that ejection failures such as clogging of nozzles due to ink that has increased viscosity in the vicinity of the nozzles and air bubbles that have entered from the nozzles, and deviations in the flight direction of ink droplets occur.

Such problems are present not only in ink jet recording heads, but also in liquid jet heads that jet liquids other than ink.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a liquid ejecting head and a liquid ejecting apparatus capable of suppressing ejection defects by removing thickened liquid and air bubbles in the vicinity of nozzles.

An aspect of the present invention for solving the above problems includes a channel substrate including a nozzle plate and having a channel formed thereon, and an energy generating element that causes a pressure change in the liquid in the channel, , a first common liquid chamber, a second common liquid chamber, and a liquid flowing from the first common liquid chamber toward the second common liquid chamber in communication with the first common liquid chamber and the second common liquid chamber. and a plurality of individual flow paths, wherein the individual flow paths are nozzles communicating with the outside, and the nozzles are arranged in the middle and are in the in-plane direction of the nozzle surface where the nozzles of the nozzle plate open. A first flow path extending in a first direction, a second flow path connected to the first flow path and extending in a second direction other than the first direction, and the second flow path a third flow path connected to and extending in a third direction other than the second direction; and a pressure chamber disposed in the third flow path and in which a pressure change is caused by the energy generating element, the The first flow path has a portion having a first cross-sectional area on the second flow path side of the nozzle, and a cross-sectional area smaller than the first cross-sectional area on the opposite side of the nozzle to the second flow path. and a portion having a second cross-sectional area.

According to another aspect, there is provided a liquid ejecting apparatus including the liquid ejecting head according to the above aspects.

1 is a plan view of a recording head according to Embodiment 1 of the present invention; FIG. 1 is a cross-sectional view of a recording head according to Embodiment 1 of the present invention; FIG. 1 is a cross-sectional view of a recording head according to Embodiment 1 of the present invention; FIG. 1 is a cross-sectional view of a recording head according to Embodiment 1 of the present invention; FIG. 1 is a cross-sectional view of a recording head according to Embodiment 1 of the present invention; FIG. 8 is a cross-sectional view of a recording head according to Embodiment 2 of the present invention; FIG. 8 is a cross-sectional view of a recording head according to Embodiment 2 of the present invention; FIG. 8 is a cross-sectional view of a recording head according to Embodiment 2 of the present invention; FIG. FIG. 5 is a cross-sectional view showing a comparative example of the recording head according to Embodiment 2 of the present invention; FIG. 8 is a plan view of a print head according to Embodiment 3 of the present invention; FIG. 8 is a cross-sectional view of a recording head according to Embodiment 3 of the present invention; FIG. 8 is a cross-sectional view of a recording head according to Embodiment 3 of the present invention; FIG. 10 is a diagram schematically showing a channel according to Embodiment 3 of the present invention; 1 is a cross-sectional view showing a print head according to an embodiment of the invention; FIG. 1 is a cross-sectional view showing a print head according to an embodiment of the invention; FIG. 1 is a cross-sectional view showing a print head according to an embodiment of the invention; FIG. 1 is a cross-sectional view showing a print head according to an embodiment of the invention; FIG. 1 is a cross-sectional view showing a print head according to an embodiment of the invention; FIG. 1 is a cross-sectional view showing a print head according to an embodiment of the invention; FIG. It is a figure which represented typically the flow path which concerns on one Embodiment of this invention. 1 is a diagram showing a schematic configuration of a recording apparatus according to an embodiment of the invention; FIG. 1 is a block diagram illustrating an ink system according to one embodiment of the invention; FIG.

The present invention will be described in detail below based on embodiments. However, the following description shows one aspect of the present invention, and can be arbitrarily changed within the scope of the present invention. In each figure, the same reference numerals denote the same members, and the description thereof is omitted as appropriate. Also, in each figure, X, Y, and Z represent three spatial axes orthogonal to each other. The directions along these axes are referred to herein as the X, Y, and Z directions. The direction in which the arrow points in each figure is defined as the positive (+) direction, and the direction opposite to the arrow is defined as the negative (-) direction. The Z direction indicates the vertical direction, the +Z direction indicates the vertically downward direction, and the −Z direction indicates the vertically upward direction.

(Embodiment 1)
An ink jet recording head, which is an example of the liquid jet head of the present embodiment, will be described with reference to FIGS. 1 to 5. FIG. FIG. 1 is a plan view of an ink jet recording head, which is an example of a liquid jet head according to Embodiment 1 of the present invention, viewed from the nozzle surface side. FIG. 2 is a cross-sectional view taken along line AA' of FIG. FIG. 3 is an enlarged view of the essential part of FIG.

As shown in the figure, an ink jet recording head 1 (hereinafter simply referred to as recording head 1), which is an example of the liquid jet head of this embodiment, includes a flow path forming substrate 10, a communication plate 15, and a nozzle plate 20 as flow path substrates. , a protective substrate 30, a case member 40, a compliance substrate 49 and the like.

The channel-forming substrate 10 is made of a silicon single crystal substrate, and a vibrating plate 50 is formed on one surface thereof. Diaphragm 50 may be a single layer or laminate selected from a silicon dioxide layer and a zirconium oxide layer.

A plurality of pressure chambers 12 constituting the individual flow paths 200 are provided in the flow path forming substrate 10 and partitioned by a plurality of partition walls. The plurality of pressure chambers 12 are arranged side by side at a predetermined pitch along the X direction in which the plurality of nozzles 21 for ejecting ink are arranged side by side. In this embodiment, one row is provided in which the pressure chambers 12 are arranged side by side in the X direction. Further, the flow path forming substrate 10 is arranged so that the in-plane directions are directions including the X direction and the Y direction. In this embodiment, the portion between the pressure chambers 12 arranged side by side in the X direction of the flow path forming substrate 10 is called a partition. This partition is formed along the Y direction. That is, the partition wall is a portion of the flow path forming substrate 10 that overlaps the pressure chamber 12 in the Y direction.

In this embodiment, only the pressure chambers 12 are provided in the flow path forming substrate 10. However, the pressure chambers 12 cross the flow paths rather than the pressure chambers 12 so as to impart flow path resistance to the ink supplied to the pressure chambers 12. A flow path resistance imparting portion having a reduced cross-sectional area may be provided.

A vibrating plate 50 is formed on one side of the channel forming substrate 10 in the -Z direction, and on this vibrating plate 50, a first electrode 60, a piezoelectric layer 70, and a second electrode 80 are formed. The piezoelectric actuator 300 is constructed by lamination by film formation and lithography. In this embodiment, the piezoelectric actuator 300 is an energy generating element that causes pressure change in the ink inside the pressure chamber 12 . Here, the piezoelectric actuator 300 is also referred to as a piezoelectric element, and refers to a portion including the first electrode 60 , the piezoelectric layer 70 and the second electrode 80 . Generally, one of the electrodes of the piezoelectric actuator 300 is used as a common electrode, and the other electrode and the piezoelectric layer 70 are patterned for each pressure chamber 12 . In this embodiment, the first electrode 60 is the common electrode of the piezoelectric actuator 300, and the second electrode 80 is the individual electrode of the piezoelectric actuator 300. However, there is no problem even if this is reversed for convenience of the drive circuit and wiring. In the above example, the diaphragm 50 and the first electrode 60 act as diaphragms, but the invention is not limited to this. It may act as a diaphragm. Also, the piezoelectric actuator 300 itself may substantially serve as a diaphragm.

A lead electrode 90 is connected to the second electrode 80 of each piezoelectric actuator 300, and a voltage is selectively applied to each piezoelectric actuator 300 via the lead electrode 90. .

A protective substrate 30 is bonded to the surface of the flow path forming substrate 10 on the side of the piezoelectric actuator 300 .

A piezoelectric actuator holding portion 31 having a space that does not hinder the movement of the piezoelectric actuator 300 is provided in the area of the protective substrate 30 facing the piezoelectric actuator 300 . The piezoelectric actuator holding portion 31 may have a space that does not hinder the movement of the piezoelectric actuator 300, and the space may or may not be sealed. Moreover, the piezoelectric actuator holding portion 31 is formed in a size that integrally covers the row of the plurality of piezoelectric actuators 300 arranged in the first direction X. As shown in FIG. Of course, the piezoelectric actuator holding portion 31 is not particularly limited to this, and may cover the piezoelectric actuators 300 individually, and is composed of two or more piezoelectric actuators 300 arranged side by side in the first direction X. It may be covered by groups.

As such a protective substrate 30, it is preferable to use a material having substantially the same coefficient of thermal expansion as the channel forming substrate 10, such as glass or ceramic material. was formed using a silicon single crystal substrate.

Further, the protective substrate 30 is provided with a through hole 32 penetrating the protective substrate 30 in the Z direction. The vicinity of the end of the lead electrode 90 drawn out from each piezoelectric actuator 300 extends so as to be exposed inside the through hole 32 and is electrically connected to the flexible cable 120 inside the through hole 32 . The flexible cable 120 is a wiring board having flexibility, and in this embodiment, a drive circuit 121, which is a semiconductor element, is mounted thereon. Note that the lead electrode 90 and the drive circuit 121 may be electrically connected without the flexible cable 120 interposed. Also, a flow path may be provided in the protection substrate 30 .

A case member 40 is fixed on the protective substrate 30 to define, together with the protective substrate 30 , a supply-side supply channel communicating with the plurality of pressure chambers 12 . The case member 40 is joined to the surface opposite to the flow path forming substrate 10 of the protection substrate 30, and is also joined to the communication plate 15, which will be described later.

The case member 40 is provided with a first liquid chamber portion 41 forming part of the first common liquid chamber 101 and a second liquid chamber portion 42 forming part of the second common liquid chamber 102. It is The first liquid chamber portion 41 and the second liquid chamber portion 42 are provided on both sides of the one row of pressure chambers 12 in the Y direction.

Each of the first liquid chamber portion 41 and the second liquid chamber portion 42 has a concave shape that opens to the -Z side surface of the case member 40, and extends over the plurality of pressure chambers 12 arranged in parallel in the X direction. are set consecutively.

The case member 40 also has an inlet 43 that communicates with the first liquid chamber 41 and introduces ink into the first liquid chamber 41 , and a second liquid chamber 42 that communicates with the second liquid chamber 42 . A discharge port 44 is provided for discharging ink from the nozzle.

Furthermore, the case member 40 is provided with a connection port 45 that communicates with the through hole 32 of the protective substrate 30 and through which the flexible cable 120 is inserted.

On the other hand, the communication plate 15, the nozzle plate 20, and the compliance substrate 49 are provided on the +Z side, which is the side opposite to the protective substrate 30, of the flow path forming substrate 10. As shown in FIG.

The nozzle plate 20 is formed with a plurality of nozzles 21 that communicate with the outside and with the pressure chambers 12 . In this embodiment, as shown in FIG. 1, a single nozzle row 22 is formed by arranging a plurality of nozzles 21 on a straight line along the X direction.

The nozzle 21 has a first hole 21a and a second hole 21b with different inner diameters. . The first hole 21a has a smaller inner diameter than the second hole 21b. The first hole 21a of the nozzle 21 is arranged on the outside side of the nozzle plate 20, that is, on the +Z side, and the second hole 21b is arranged on the -Z side of the nozzle plate 20, which is the side of the first flow path 201, which will be described later in detail. It is

By providing the first hole 21a having a relatively small inner diameter in the nozzle 21 in this way, the flow velocity of the ink can be improved, and the ejection velocity of the ejected ink droplets can be improved. In addition, by providing the second hole 21b having a relatively large inner diameter in the nozzle 21, the ink in the individual channel 200 flows from the first common liquid chamber 101 toward the second common liquid chamber 102, which will be described later in detail. , the portion unaffected by the flow of circulation can be reduced when circulation is performed. As a result, the velocity gradient increases, and the ink thickened by the nozzles 21 can be easily removed.

In this embodiment, the inner diameter of the nozzle 21 is changed stepwise by the first hole 21a and the second hole 21b. Thus, the inner surface of the nozzle 21 may be an inclined surface that is inclined with respect to the Z direction. Further, the shape of the nozzle 21 when viewed from above in the Z direction is not particularly limited, and may be circular, elliptical, rectangular, polygonal, bell-shaped, or the like.

Such a nozzle plate 20 can be formed of, for example, a metal such as stainless steel (SUS), an organic material such as polyimide resin, or a flat plate material such as silicon. Moreover, the plate thickness of the nozzle plate 20 is preferably 60 μm or more and 100 μm or less. By using the nozzle plate 20 having such a plate thickness, it is possible to improve the handling property of the nozzle plate 20 and improve the assembling property of the recording head 1 .

The communication plate 15 has a first communication plate 151 and a second communication plate 152 in this embodiment. The first communication plate 151 and the second communication plate 152 are laminated in the Z direction such that the first communication plate 151 is on the flow path forming substrate 10 side and the second communication plate 152 is on the nozzle plate 20 side in the Z direction.

The first communication plate 151 and the second communication plate 152 constituting the communication plate 15 can be made of metal such as stainless steel, glass, ceramic material, or the like. The communication plate 15 is preferably made of a material having substantially the same coefficient of thermal expansion as the channel forming substrate 10. In this embodiment, the communicating plate 15 is formed using a silicon single crystal substrate of the same material as the channel forming substrate 10. .

The communicating plate 15 includes a first communicating portion 16 communicating with the first liquid chamber portion 41 of the case member 40 to constitute a part of the first common liquid chamber 101, and a second liquid chamber portion 42 of the case member 40. A second communicating portion 17 and a third communicating portion 18 are provided that are in communication with each other to constitute a part of the second common liquid chamber 102 . In addition, the communication plate 15 includes a flow path for communicating the first common liquid chamber 101 and the pressure chamber 12, a flow path for communicating the pressure chamber 12 and the nozzle 21, and a nozzle 21 and the nozzle 21, which will be described later in detail. 2, a channel communicating with the common liquid chamber 102 is provided. These channels provided in the communication plate 15 constitute part of the individual channels 200 .

The first communicating portion 16 is provided at a position overlapping the first liquid chamber portion 41 of the case member 40 in the Z direction, and is open to both the +Z side surface and the -Z side surface of the communicating plate 15. That is, it is provided so as to pass through the communication plate 15 in the Z direction. The first communicating portion 16 constitutes the first common liquid chamber 101 by communicating with the first liquid chamber portion 41 on the -Z side. That is, the first common liquid chamber 101 is composed of the first liquid chamber portion 41 of the case member 40 and the first communication portion 16 of the communication plate 15 . Also, the first communication portion 16 extends in the Y direction to a position overlapping the pressure chamber 12 in the Z direction on the +Z side. The first common liquid chamber 101 may be configured by the first liquid chamber portion 41 of the case member 40 without providing the first communication portion 16 in the communication plate 15 .

The second communicating portion 17 is provided at a position overlapping the second liquid chamber portion 42 of the case member 40 in the Z direction, and is provided to open on the −Z side surface of the first communicating plate 151 . Further, the second communication portion 17 is provided so as to be widened toward the nozzle 21 in the +Y direction on the +Z side.

The third communicating portion 18 is provided to penetrate the second communicating plate 152 in the Z direction at a position where it communicates with the portion widened toward the nozzle 21 in the +Y direction on the +Z side of the second communicating portion 17 . . The +Z side opening of the third communicating portion 18 is covered with a nozzle plate 20 .

A second common liquid chamber 102 is constituted by the second communication portion 17 and the third communication portion 18 provided in the communication plate 15 and the second liquid chamber portion 42 provided in the case member 40 . The second common liquid chamber 102 may be configured by the second liquid chamber portion 42 of the case member 40 without providing the second communication portion 17 and the third communication portion 18 in the communication plate 15 .

A compliance substrate 49 having a compliance portion 494 is provided on the +Z side surface of the communication plate 15 where the first communication portion 16 opens. The compliance substrate 49 seals the opening of the first common liquid chamber 101 on the side of the nozzle surface 20a.

Such a compliance substrate 49 in this embodiment includes a sealing film 491 made of a flexible thin film and a fixed substrate 492 made of a hard material such as metal. Since the region of the fixed substrate 492 facing the first common liquid chamber 101 is an opening 493 that is completely removed in the thickness direction, part of the wall surface of the first common liquid chamber 101 is flexible. The compliance portion 494 is a flexible portion sealed only by the sealing film 491 provided. By providing the compliance portion 494 on a part of the wall surface of the first common liquid chamber 101 in this manner, the pressure fluctuation of the ink inside the first common liquid chamber 101 can be absorbed by the compliance portion 494 deforming.

In this embodiment, the first common liquid chamber 101 is provided so as to open on the +Z side where the nozzles 21 open, so that the nozzle plate 20 and the compliance portion 494 are aligned in the Z direction, which is the direction perpendicular to the nozzle surface 20a. , is arranged on the +Z side, which is the same side as the individual flow path 200 having the pressure chamber 12 and the nozzle 21 . In this way, by arranging the compliance portion 494 on the same side as the nozzle 21 with respect to the individual channel 200, the compliance portion 494 can be provided in a region where the nozzle 21 is not provided, and the compliance portion 494 can be relatively It can be provided over a large area. Further, by arranging the compliance portion 494 and the nozzle 21 on the same side with respect to the individual channel 200, the compliance portion 494 is arranged at a position close to the individual channel 200, and the pressure of the ink in the individual channel 200 is reduced. Fluctuations can be effectively absorbed by the compliance section 494 .

Further, the flow path forming substrate 10, the communication plate 15, the nozzle plate 20, the compliance substrate 49, etc., which constitute the flow path substrate, communicate with the first common liquid chamber 101 and the second common liquid chamber 102, and the first common liquid chamber 101 communicates with the second common liquid chamber . A plurality of individual channels 200 are provided for sending the ink in the common liquid chamber 101 to the second common liquid chamber 102 . Here, the individual channel 200 of the present embodiment communicates with the first common liquid chamber 101 and the second common liquid chamber 102 , is provided for each nozzle 21 , and includes the nozzle 21 . The three individual flow paths 200 adjacent in the X direction, which is the direction in which the nozzles 21 are arranged side by side, are provided in communication with the first common liquid chamber 101 and the second common liquid chamber 102, respectively. That is, the plurality of individual flow paths 200 provided for each nozzle 21 are provided so as to communicate only with the first common liquid chamber 101 and the second common liquid chamber 102, respectively. Except for the first common liquid chamber 101 and the second common liquid chamber 102, they are not communicated with each other. That is, in the present embodiment, a channel provided with one nozzle 21 and one pressure chamber 12 is referred to as an individual channel 200, and each individual channel 200 is connected to the first common liquid chamber 101 and the second common liquid chamber 101. It is provided so as to communicate only with the chamber 102 .

Further, in the present embodiment, a channel of the individual channel 200 closer to the first common liquid chamber 101 than the nozzle 21 is referred to as an upstream channel, and a channel closer to the second common liquid chamber 102 than the nozzle 21 of the individual channel 200 is referred to as an upstream channel. The channel is called the downstream channel.

As shown in FIG. 2 , the individual channel 200 includes a nozzle 21 , a pressure chamber 12 forming a third channel, a first channel 201 , a second channel 202 and a supply channel 203 .

The pressure chambers 12 are provided in the channel forming substrate 10 as described above, and extend in the Y direction, which is the third direction. That is, the pressure chamber 12 has one end in the Y direction connected to the supply path 203 and the other end in the Y direction connected to the second flow path 202 . is provided in In other words, the extending direction of the pressure chambers 12 is the direction in which ink flows in the pressure chambers 12 .

Since the pressure chamber 12 of the present embodiment extends in the Y direction as described above, the second flow path 202 described later in detail extends in a direction other than the Z direction, which is the second direction. It can be said that it has been extended to

Moreover, the pressure chamber 12 constitutes a third flow path extending in a direction other than the Z direction. The third flow path of this embodiment is composed only of the pressure chamber 12 . Of course, it is not limited to this, and as described above, when the flow path resistance imparting portion having a narrower cross-sectional area than the pressure chamber 12 is provided at the end of the pressure chamber 12 so as to impart flow path resistance, The pressure chamber 12 and the flow path resistance applying section constitute a third flow path. In addition, although the pressure chamber 12 of the present embodiment extends in the Y direction, it may extend in a direction different from the Z direction, which is the second direction, and may extend in the X direction. may be set.

The supply path 203 connects the pressure chamber 12 and the first common liquid chamber 101, and is provided to penetrate the first communication plate 151 in the Z direction. That is, one end of the supply path 203 on the +Z side communicates with the first common liquid chamber 101 , and the other end on the −Z side communicates with the pressure chamber 12 . Such a supply path 203 extends in the Z direction. Here, the direction in which the supply path 203 extends means the direction in which the ink flows in the supply path 203 .

The first flow path 201 extends in the in-plane direction of the nozzle plate 20, that is, in the in-plane direction of the nozzle surface 20a. In this embodiment, the first flow path 201 extends in the Y direction among directions including the X direction and the Y direction, which are in-plane directions of the nozzle surface 20a. That is, the first direction in this embodiment is the Y direction.

The direction in which the first flow path 201 extends is the direction in which the ink flows in the first flow path 201 . In this embodiment, the first flow path 201 communicates with the second flow path 202 at one end in the Y direction and communicates with the second common liquid chamber 102 at the other end in the Y direction. Ink flows in the Y direction. Therefore, the direction in which the first channel 201 extends is the Y direction.

Such a first flow path 201 is provided along the Y direction between the second communication plate 152 and the nozzle plate 20 . Specifically, the first flow path 201 is formed by providing a recess in the second communication plate 152 and covering the opening of the recess with the nozzle plate 20 . Note that the first flow path 201 is not particularly limited to this, and a recess may be provided in the nozzle plate 20 and the recess of the nozzle plate 20 may be covered by the second communication plate 152. You may make it provide a recessed part in both nozzle plate 20. FIG.

Here, the first flow path 201 of the present embodiment includes a first portion 201a having a first cross-sectional area, and a first portion 201a having a smaller cross-sectional area than the first cross-sectional area of the first portion 201a. and a second portion 201b which is a portion having a cross-sectional area of 2.

Here, the cross-sectional area of a flow path is the area of a cross section across the direction in which ink flows in the flow path. Therefore, the cross-sectional area of the first flow path 201 is the area of the cross section that traverses the Y direction, which is the direction in which the ink flows. That is, the direction crossing the Y direction of the first channel 201 is the direction including the X direction and the Z direction, and is the cross-sectional area of the first channel 201 in the direction including the X direction and the Y direction.

In this embodiment, the first portion 201a and the second portion 201b are formed to have the same width in the X direction. The second cross-sectional area of the second portion 201b is made smaller than the first cross-sectional area of 201a. Specifically, as shown in FIG. 3, the height _h2 of the second portion 201b is smaller than the height _h1 of the first portion 201a. In this embodiment, the height difference between the first portion 201a and the second portion 201b is such that the ceiling of the second portion 201b on the side opposite to the nozzles 21 is closer to the nozzle plate 20 than the first portion 201a in the Z direction. The close position makes the height _h2 of the second portion 201b smaller than the height _h1 of the first portion 201a.

The first portion 201a and the second portion 201b are arranged side by side in the Y direction, which is the direction in which ink flows. In this embodiment, the first portion 201a is provided on the second flow path 202 side, and the second portion 201b is provided on the second common liquid chamber 102 side.

The second flow path 202 is connected to the first flow path 201, and extends in a second direction other than the Y direction, which is the first direction in which the first flow path 201 extends, and in the Z direction in this embodiment. deferred. Here, the direction in which the second channel 202 extends means the direction in which the ink flows in the second channel 202 . In this embodiment, the second flow path 202 is provided through the communication plate 15 in the Z direction, communicates with the pressure chamber 12 at one end in the Z direction, and communicates with the first flow path 201 at the other end in the Z direction. , the pressure chamber 12 and the first channel 201 are communicated with each other. Therefore, the ink flows in the Y direction within the second channel 202 .

The nozzle 21 is arranged at a position communicating with the middle of the first flow path 201 . That is, the nozzle 21 is provided so that one end communicates with the middle of the first flow path 201 and the other end opens to the nozzle surface 20a on the +Z side of the nozzle plate 20 so as to communicate with the outside.

Here, the fact that the nozzle 21 is provided so as to communicate with the middle of the first flow path 201 means that the nozzle 21 is arranged at a position overlapping the first flow path 201 when viewed from above in the Z direction. Say things. By the way, when the nozzle 21 is arranged at a position overlapping the second flow path 202 when viewed in plan from the Z direction, it does not mean that it is provided so as to communicate with the middle of the first flow path 201. . That is, the first flow path 201 of this embodiment is a portion that does not overlap the second flow path 202 in the Z direction.

Further, the nozzle 21 is provided at a position communicating with the first portion 201 a of the first flow path 201 . That is, the first flow path 201 has a first portion 201 a on the second flow path 202 side of the nozzle 21 and a second common liquid chamber 102 side of the nozzle 21 opposite to the second flow path 202 . two portions 201b; Here, the first flow path 201 includes the first portion 201a having the first cross-sectional area on the second flow path 202 side of the nozzle 21 means that the first portion 201a including the portion to which the nozzle 21 communicates. say that In other words, the nozzle 21 provided at a position communicating with the second portion 201b is not included. Further, in the present embodiment, the nozzle 21 is provided in communication with the second portion 201b side in the first portion 201a. That is, the second portion 201b is provided close to the downstream side of the nozzle 21 .

The cross-sectional area of the first channel 201 with which the nozzle 21 communicates is preferably smaller than the cross-sectional area of the second channel 202 . That is, the first cross-sectional area of the first portion 201 a of the first channel 201 is preferably smaller than the cross-sectional area of the second channel 202 . In this embodiment, the first portion 201a and the second flow path 202 are formed with the same width in the X direction, which is the direction in which the nozzles 21 are arranged side by side, and the height of the first portion 201a of the first flow path 201 in the Z direction. The cross _- sectional area of the first portion 201a is made smaller than the cross-sectional area of the second flow path 202 by making the height h1 lower than the height _h3 of the second flow path 202 in the Y direction.

Such an individual channel 200 includes a supply channel 203 , a pressure chamber 12 , a second channel 202 , a supply channel 203 , a pressure chamber 12 , a second channel 202 , and a second channel 202 , in order from the upstream side communicating with the first common liquid chamber 101 to the downstream side communicating with the second common liquid chamber 102 . It has a first channel 201 . In other words, in the present embodiment, the individual flow path 200 has the pressure chambers 12 and the nozzles 21 from upstream to downstream with respect to the flow of ink from the first common liquid chamber 101 to the second common liquid chamber 102 . are arranged in this order.

In such an individual channel 200, ink flows from the first common liquid chamber 101 through the individual channel 200 to the second common liquid chamber 102, so-called circulation. In addition, by driving the piezoelectric actuator 300, the pressure of the ink in the pressure chamber 12 is changed to increase the pressure of the ink in the nozzle 21, thereby ejecting ink droplets from the nozzle 21 to the outside. When the ink flows from the first common liquid chamber 101 through the individual channels 200 to the second common liquid chamber 102, the piezoelectric actuator 300 may be driven. The piezoelectric actuator 300 may be driven when ink does not flow into the two common liquid chambers 102 . Ink may temporarily flow from the second common liquid chamber 102 to the first common liquid chamber 101 due to a pressure change caused by driving the piezoelectric actuator 300 .

In addition, in the print head 1 of the present embodiment, the nozzles 21 are communicated in the middle of the first flow path 201 , so that the ink that has increased in viscosity due to drying by the nozzles 21 is moved downstream by the ink flowing through the first flow path 201 . can flow into the second common liquid chamber 102 on the side. Therefore, the thickened ink is prevented from accumulating in the nozzles 21 and their vicinity, and clogging of the nozzles 21 due to the thickened ink and ejection defects such as deviation of the flight direction of the ink droplets ejected from the nozzles 21 are prevented. can be prevented from occurring.

On the other hand, for example, when the nozzle 21 is arranged at a position communicating with the second flow path 202, that is, when the nozzle 21 is arranged at a position overlapping the second flow path 202 when viewed from the Z direction. Ink that is thickened by being dried by the nozzles 21 tends to stay at the corners between the second flow paths 202 and the nozzle plate 20, particularly at the corners opposite to the first flow paths 201 in the Y direction. In addition, when the thickened ink stays in the vicinity of the nozzle 21, clogging of the nozzle 21 due to the thickened ink and ejection failure such as deviation of the flight direction of the ejected ink droplets are likely to occur.

In this embodiment, by connecting the nozzles 21 to the first channel 201 extending in the Y direction, the nozzles 21 are separated from the corners of the nozzle plate 20 and the second channels 202 where ink tends to stagnate. The ink thickened by the nozzles 21 does not easily stay in the vicinity of the nozzles 21, and the thickened ink can be easily removed.

In addition, by connecting the nozzle 21 to the middle of the first flow path 201 extending in the Y direction, air bubbles entering from the nozzle 21 are removed by the ink flowing through the first flow path 201 to the second common liquid on the downstream side. It can flow to the chamber 102 side. Therefore, the air bubbles entering from the nozzles 21 are prevented from entering the pressure chambers 12 and the first common liquid chamber 101, and the pressure fluctuations of the ink in the pressure chambers 12 are absorbed by the air bubbles entering the pressure chambers 12. It is possible to suppress ejection defects of ink droplets caused by the above. Incidentally, when the nozzle 21 is provided at a position that communicates with the second flow path 202, air bubbles entering from the nozzle 21 tend to move toward the pressure chamber 12 against the flow of ink due to buoyancy. If air bubbles enter the pressure chambers 12 from the nozzles 21, the air bubbles may absorb the pressure fluctuations of the ink in the pressure chambers 12, resulting in ejection failure of ink droplets.

Further, by providing the first portion 201a having the first cross-sectional area closer to the second flow path 202 than the nozzle 21, the flow path resistance from the pressure chamber 12 to the nozzle 21 is suppressed from increasing, and the pressure is increased. A pressure loss from the chamber 12 to the nozzle 21 can be reduced, and a decrease in the weight of ink droplets ejected from the nozzle 21 can be suppressed. Incidentally, when the first flow path 201 is composed only of the second portion 201b, the resistance of the flow path from the pressure chamber 12 to the nozzle 21 is large, and the pressure loss is large. Become. For this reason, the piezoelectric actuator 300 must be driven with a higher drive voltage, resulting in lower ejection efficiency. In this embodiment, by connecting the nozzles 21 to the first portion 201a, it is possible to suppress a decrease in the weight of the ink droplets. can be improved. Further, by communicating the nozzle 21 with the first portion 201a, the position of the nozzle 21 communicating with the middle of the first flow path 201 is not restricted. That is, when the first flow path 201 is configured only by the second portion 201b, the nozzle 21 is provided at a position close to the second flow path 202 in order to reduce the pressure loss from the pressure chamber 12 to the nozzle 21. However, in the present embodiment, pressure loss can be reduced by providing the first portion 201a on the second flow path 202 side of the nozzle 21, including the nozzle 21. There is no need to arrange the nozzles 21 at positions close to the path 202, and the degree of freedom in arrangement of the nozzles 21 can be increased.

Further, by providing the second portion 201b on the downstream side of the nozzle 21, the flow velocity of the ink flowing through the second portion 201b can be increased. , the second portion 201b can be removed by ink flowing at a relatively high flow velocity. That is, the ink thickened by the nozzles 21 and the bubbles entering from the nozzles 21 tend to flow toward the downstream second portion 201b, and the bubbles flowing into the second portion 201b flow downstream at a high flow velocity. Therefore, it is difficult for the liquid to flow backward toward the second flow path 202 on the upstream side. Therefore, thickened ink and air bubbles are less likely to remain in the vicinity of the nozzle 21 and less likely to flow back upstream.

In addition, in the present embodiment, by connecting the nozzle 21 to the first portion 201a of the first flow path 201 having a smaller cross-sectional area than the second flow path 202, the liquid flows through the first flow path 201 directly above the nozzle 21 during circulation. Since the flow velocity of the ink can be made faster than that of the ink flowing through the second channel 202, the ink that has been thickened by the nozzles 21 and the air bubbles that have entered from the nozzles 21 are moved downstream by the ink flowing through the first channel 201. can easily flow to the second common liquid chamber 102 side. Therefore, it is possible to reduce the accumulation of the thickened ink and the invaded air bubbles in the vicinity of the nozzle 21, thereby suppressing the occurrence of defective ejection of ink droplets.

Incidentally, for example, the nozzle 21 is provided at a position communicating with the second flow path 202, and the cross-sectional area of the second flow path 202 on the nozzle 21 side is made smaller than the cross-sectional area on the pressure chamber 12 side. Although it is possible to consider a configuration in which the flow velocity on the nozzle 21 side is increased to flow the thickened ink downstream, even in such a configuration, the air bubbles entering from the nozzle 21 are pushed against the flow of the ink by buoyant force, causing pressure chambers to flow. 12 may be invaded. In the present embodiment, since the extending direction of the first flow path 201 to which the nozzle 21 communicates in the middle is the direction that intersects the Z direction, which is the vertical direction, the entry of air bubbles into the pressure chamber 12 is suppressed. can do.

In this embodiment, the first channel 201 of the individual channel 200 and the second common liquid chamber 102 are directly connected, but the present invention is not limited to this. Another flow path may be provided between the common liquid chamber 102 and the common liquid chamber 102 . For example, when another channel is provided between the first channel 201 and the second common liquid chamber 102, the distance from the nozzle 21 of the first channel 201 to the second channel 202 is It is preferably shorter than the distance from the nozzle 21 of the first channel 201 to the other channels.

The flow path resistance from the nozzle 21 to the pressure chamber 12 is preferably smaller than the flow path resistance from the nozzle 21 to the second common liquid chamber 102 . That is, the flow path resistance between the upstream side of the first flow path 201 and the second flow path 202 from the position where it communicates with the nozzle 21 is greater than the flow path resistance on the downstream side from the position where the first flow path 201 communicates with the nozzle 21. is preferably small. As a result, the pressure loss from the pressure chamber 12 to the nozzle 21 can be reduced, the weight of the ink droplet ejected from the nozzle 21 can be suppressed, and the ejection efficiency can be improved.

Further, in the individual channel 200, the channel resistance from the nozzle 21 to the second common liquid chamber 102 is −50% or more and +50% or less with respect to the channel resistance from the nozzle 21 to the first common liquid chamber 101. is preferred.

That is, the flow path resistance from the nozzle 21 to the first common liquid chamber 101 includes the portion of the first flow path 201 from the position where the nozzle 21 communicates to the second flow path 202 side, the second flow path 202, and the supply flow resistance. It is the flow path resistance with the path 203 . Further, the channel resistance from the nozzle 21 to the second common liquid chamber 102 is the channel resistance of the portion from the position where the nozzle 21 communicates with the first channel 201 to the second common liquid chamber 102 . Then, the channel resistance from the nozzle 21 to the second common liquid chamber 102 of the individual channel 200 is -50% or more and +50% or less with respect to the channel resistance from the nozzle 21 to the first common liquid chamber 101. By doing so, the position of the ink meniscus of the nozzle 21 can be easily managed. For example, when the direction of circulation is reversed with respect to the flow of ink from the first common liquid chamber 101 to the second common liquid chamber 102, that is, the ink flowing from the second common liquid chamber 102 to the first common liquid chamber 101 Even in the case of a flow of , the position of the meniscus of the ink in the nozzle 21 can be easily aligned by setting the flow path resistance as described above. Incidentally, it is preferable to make the flow path resistance from the nozzle 21 to the first common liquid chamber 101 and the flow path resistance from the nozzle 21 to the second common liquid chamber 102 the same. This makes it easier to align the positions of the ink meniscuses of the nozzles 21 .

As described above, the ink jet recording head 1, which is an example of the liquid jet head of the present embodiment, includes the nozzle plate 20, the channel substrate in which the channels are formed, and the pressure applied to the ink, which is the liquid in the channels. and a piezoelectric actuator 300 that is an energy generating element that generates a change. and a plurality of individual channels 200 through which ink flows from the first common liquid chamber 101 toward the second common liquid chamber 102 in communication with the nozzles 21 communicating with the outside, and the nozzles 21 is disposed in the middle and extends in the Y direction, which is the first direction that is the in-plane direction of the nozzle surface 20a of the nozzle plate 20 where the nozzles 21 open, and the first flow path 201 and a second flow path 202 connected to and extending in the Z direction, which is a second direction other than the Y direction, and a second flow path 202 connected to and extending in the Y direction, which is a third direction other than the Z direction. and a pressure chamber 12 that is arranged in the third flow path and causes a pressure change due to a piezoelectric actuator 300. A first portion 201a having a cross-sectional area of 1 and a second cross-sectional area having a smaller cross-sectional area than the first cross-sectional area are provided on the opposite side of the nozzle 21 from the second flow path 202. two portions 201b;

In this way, by connecting the nozzle 21 in the middle of the first flow path 201 extending in the Y direction, the ink that has increased in viscosity due to being dried by the nozzle 21 is moved downstream by the ink flowing through the first flow path 201 . can flow into the second common liquid chamber 102 on the side. Therefore, the nozzles 21 can be arranged away from the corners of the second flow passages 202 and the nozzle plate 20 where ink is stagnant, and the ink thickened by the nozzles 21 can flow through the second flow passages 202 and the nozzle plate. 20, clogging of the nozzles 21 due to thickened ink or air bubbles, and clogging of the nozzles 21. can be suppressed. In addition, it is possible to prevent the air bubbles entering from the nozzle 21 from staying at the corner between the second channel 202 and the nozzle plate 20, and prevent the air bubbles entering from the nozzle 21 from moving to the pressure chamber 12 side. can be suppressed, and ejection failure of ink droplets can be suppressed.

In addition, by providing the first portion 201a, which is the first cross-sectional area on the second flow path side of the nozzle 21, the pressure loss from the pressure chamber 12 to the nozzle 21 is reduced, and the ink droplet ejected from the nozzle 21 is reduced. weight reduction can be suppressed.

Furthermore, by providing the second portion 201b having the second cross-sectional area closer to the second common liquid chamber 102 than the nozzles 21, the flow velocity of the ink flowing through the second portion 201b can be increased. The viscous ink and air bubbles entering from the nozzle 21 can be removed by the ink flowing through the second portion 201b at a relatively high speed, and the thickened ink and air bubbles are less likely to flow back upstream.

Also, in the print head 1 of the present embodiment, the cross-sectional area of the first flow path 201 is preferably smaller than the cross-sectional area of the second flow path 202 . That is, the first cross-sectional area of the smaller first portion 201a of the cross-sectional area of the first flow path 201 is preferably smaller than the cross-sectional area of the second flow path 202 across the ink flow. In this way, by connecting the nozzle 21 to the first portion 201a of the first flow path 201 having a smaller cross-sectional area than the second flow path 202, the flow rate of the ink flowing through the first flow path 201 immediately above the nozzle 21 during circulation is increased. can be made faster than the ink flowing through the second flow path 202 , the ink that has been thickened by the nozzles 21 and the air bubbles that have entered from the nozzles 21 are moved to the downstream side by the ink flowing through the first flow path 201 . It is possible to easily flow to the second common liquid chamber 102 side. Therefore, it is possible to reduce the accumulation of the thickened ink and the invaded air bubbles in the vicinity of the nozzle 21, thereby suppressing the occurrence of defective ejection of ink droplets.

In addition, in the recording head 1 of the present embodiment, the second portion 201b, which is the portion having the second cross-sectional area, has a nozzle surface through which the nozzles 21 open, with respect to the first portion 201a, which is the portion having the first cross-sectional area. By reducing the height in the Z direction, which is the direction perpendicular to 20a, the cross-sectional area is smaller than that of the first portion 201a. In this way, the second portion 201b is formed with a reduced height in the Z direction rather than the X direction, which is the direction in which the nozzles 21 are arranged side by side. The first channels 201 can be densely arranged in the X direction, and the rigidity of the walls between the first channels 201 adjacent in the X direction can be improved so that the walls can be bent by the pressure of the ink in the channels. It is possible to suppress variations in ejection characteristics of ink droplets due to deformation. That is, when ink droplets are simultaneously ejected from the nozzles 21 on both sides of the nozzles 21 that eject ink droplets, pressure is applied to the wall between the adjacent first flow paths 201 from both sides at the same timing. In this case, pressure is applied from both sides of the wall regardless of the rigidity of the wall, so the wall is difficult to deform. On the other hand, when ink droplets are not ejected from the nozzles 21 on both sides of the nozzles 21 that eject ink droplets, pressure is applied to only one side of the wall between the adjacent first flow paths 201 . At this time, if the rigidity of the wall is low, the wall deforms and absorbs pressure fluctuations, deteriorating the ejection characteristics of the ink droplets. Therefore, the ejection characteristics of the ink droplets vary due to the difference in the conditions for ejecting the ink droplets from any of the plurality of nozzles 21 . In the present embodiment, the second portion 201b of the first flow path 201 is formed by reducing the height in the Z direction without changing the width in the X direction with respect to the first portion 201a. Since it is possible to suppress the deterioration of the rigidity of the wall between the second portions 201b adjacent in the direction, it is possible to suppress the occurrence of variations in ink droplet ejection characteristics.

In addition, in the recording head 1 of the present embodiment, in the individual flow path 200, the flow path resistance on the downstream side of the nozzle 21 is −50% or more and +50% or less with respect to the flow path resistance on the upstream side. preferable. In this way, the flow path resistance on the downstream side of the nozzle 21 of the individual flow path 200 is -50% or more and +50% or less with respect to the flow path resistance on the upstream side, so that the direction of ink flowing through the individual flow path 200 Regardless, it is easy to manage the position of the ink meniscus of the nozzle 21 .

In this embodiment, the height of the first flow path 201 in the Z direction and the height of one side opposite to the nozzle 21 are narrowed to form the first portion 201a and the first portion 201a. Although the step surface along the Z direction is formed in the portion where the height in the Z direction is different between the 201a and the second portion 201b, the present invention is not particularly limited to this. FIG. 4 shows a modified example of the first channel 201 of this embodiment. 4 is an enlarged cross-sectional view of a main portion showing a modification of the first flow path according to Embodiment 1 of the present invention, and is a cross-sectional view of the main portion according to line AA' of FIG. be.

As shown in FIG. 4, the second portion 201b is formed by narrowing the ceiling on the opposite side of the nozzle 21 in the Z direction compared to the first portion 201a. Further, the connecting portion where the height of the first portion 201a and the second portion 201b is reduced forms an inclined surface 201c inclined with respect to the direction perpendicular to the nozzle surface 20a. That is, the inclined surface 201c is formed on the ceiling such that the height in the Z direction gradually decreases from the first portion 201a toward the second portion 201b in the Y direction.

Thus, by providing the inclined surface 201c on the ceiling of the connecting portion between the first portion 201a and the second portion 201b, even if the air bubbles 210 from the second portion 201b rise to the vicinity of the ceiling due to buoyancy, the first flow The ink flowing through the path 201 can move downstream along the inclined surface 201c, and the accumulation of the bubbles 210 in the vicinity of the nozzle 21 can be suppressed. Incidentally, in the configuration shown in FIG. 3 described above, the ceiling portion connecting the first portion 201a and the second portion 201b is provided with a step having a surface along the Z direction. There is a risk that it may move to the side and be caught in a step, preventing it from flowing downstream.

Also, the second portion 201b is formed by narrowing the ceiling on the opposite side of the nozzle 21 in the Z direction, but the present invention is not particularly limited to this. Here, FIG. 5 shows a modified example of the first channel 201 . 5 is an enlarged cross-sectional view of a main portion showing a modification of the first flow path according to Embodiment 1 of the present invention, and is a cross-sectional view of the main portion according to line AA' of FIG. be.

As shown in FIG. 5, the first portion 201a of the first flow path 201 is formed by narrowing the bottom surface on the nozzle 21 side in the direction perpendicular to the nozzle surface 20a. That is, the ceiling portion of the connecting portion between the first portion 201a and the second portion 201b is flush with each other. In such a first flow path 201, even if bubbles entering from the nozzle 21 move in the -Z direction due to buoyancy, the bubbles are prevented from staying at the connecting portion between the first portion 201a and the second portion 201b. Therefore, it is possible to suppress ejection failure due to retention of air bubbles in the vicinity of the nozzle 21 .

Also, in the present embodiment, the nozzle plate 20 and the compliance substrate 49 are provided separately, but the present invention is not particularly limited to this. For example, the nozzle plate 20 may be provided with a size that covers the opening of the first common liquid chamber 101 and the compliance portion 494 may be provided on a part of the nozzle plate 20 . The nozzle plate 20 provided with such a compliance portion 494 can be manufactured from a resin film such as polyimide or a metal material such as stainless steel.

(Embodiment 2)
FIG. 6 is a cross-sectional view of an ink jet recording head, which is an example of a liquid jet head according to Embodiment 2 of the present invention, and is a cross-sectional view according to line AA' in FIG. FIG. 7 is a cross-sectional view of the essential part taken along line BB' of FIG. In addition, the same code|symbol is attached|subjected to the member similar to embodiment mentioned above, and the overlapping description is abbreviate|omitted.

As shown in FIGS. 6 and 7, the first flow path 201 includes a first portion 201a having a first cross-sectional area on the second flow path 202 side of the nozzle 21, and a second common liquid chamber 201 of the nozzle 21. and a second portion 201b having a second cross-sectional area smaller than the first cross-sectional area on the 102 side.

As shown in FIG. 7, the second portion 201b is formed by narrowing the width of the first portion 201a in the X direction, which is the direction in which the nozzles 21 are arranged. That is, the width _w2 of the second portion 201b in the X direction is narrower than the width _w1 of the first portion 201a in the X direction. Further, in the present embodiment, the width in the X direction of the second portion 201b is formed by narrowing the first portion 201a from both sides in the X direction.

The first portion 201a and the second portion 201b are provided at the same height in the Z direction.

As described above, the ink jet recording head 1, which is an example of the liquid jet head of the present embodiment, includes the nozzle plate 20, the channel substrate in which the channels are formed, and the pressure applied to the ink, which is the liquid in the channels. and a piezoelectric actuator 300 that is an energy generating element that generates a change. and a plurality of individual channels 200 through which ink flows from the first common liquid chamber 101 toward the second common liquid chamber 102 in communication with the nozzles 21 communicating with the outside, and the nozzles 21 is disposed in the middle and extends in the Y direction, which is the first direction that is the in-plane direction of the nozzle surface 20a of the nozzle plate 20 where the nozzles 21 open, and the first flow path 201 and a second flow path 202 connected to and extending in the Z direction, which is a second direction other than the Y direction, and a second flow path 202 connected to and extending in the Y direction, which is a third direction other than the Z direction. and a pressure chamber 12 that is arranged in the third flow path and causes a pressure change due to a piezoelectric actuator 300. A first portion 201a having a cross-sectional area of 1 and a second cross-sectional area having a smaller cross-sectional area than the first cross-sectional area are provided on the opposite side of the nozzle 21 from the second flow path 202. two portions 201b;

In this way, by connecting the nozzle 21 in the middle of the first flow path 201 extending in the Y direction, the ink that has increased in viscosity due to being dried by the nozzle 21 is moved downstream by the ink flowing through the first flow path 201 . can flow into the second common liquid chamber 102 on the side. Therefore, the nozzles 21 can be arranged away from the corners of the second flow passages 202 and the nozzle plate 20 where ink is stagnant, and the ink thickened by the nozzles 21 can flow through the second flow passages 202 and the nozzle plate. 20, clogging of the nozzles 21 due to thickened ink or air bubbles, and clogging of the nozzles 21. can be suppressed. In addition, it is possible to prevent the air bubbles entering from the nozzle 21 from staying at the corner between the second channel 202 and the nozzle plate 20, and prevent the air bubbles entering from the nozzle 21 from moving to the pressure chamber 12 side. can be suppressed, and ejection failure of ink droplets can be suppressed.

In addition, by providing the first portion 201a, which is the first cross-sectional area on the second flow path side of the nozzle 21, the pressure loss from the pressure chamber 12 to the nozzle 21 is reduced, and the ink droplet ejected from the nozzle 21 is reduced. weight reduction can be suppressed.

Furthermore, by providing the second portion 201b having the second cross-sectional area closer to the second common liquid chamber 102 than the nozzles 21, the flow velocity of the ink flowing through the second portion 201b can be increased. The viscous ink and air bubbles entering from the nozzle 21 can be removed by the ink flowing through the second portion 201b at a relatively high speed, and the thickened ink and air bubbles are less likely to flow back upstream.

In addition, in the recording head 1 of the present embodiment, the second portion 201b, which is the portion having the second cross-sectional area, is arranged in the direction in which the nozzles 21 are arranged with respect to the first portion 201a, which is the portion having the first cross-sectional area. By narrowing the width in a certain X direction, the first portion 201a is formed with a smaller cross-sectional area than the first cross-sectional area. Thus, by reducing the width in the X direction and providing the second portion 201b, it is possible to suppress the height of the first portion 201a in the Z direction. Therefore, the thickness of the communication plate 15 in the Z direction can be made relatively thin. As a result, the passage length of the second passage 202 is made relatively short, the pressure loss from the pressure chamber 12 to the nozzle 21 is reduced, and the weight of the ink droplet ejected from the nozzle 21 is suppressed. can do.

Further, by narrowing the width of the second portion 201b in the X direction, no step is formed on the ceiling on the opposite side of the nozzle 21 in the Z direction at the connecting portion between the first portion 201a and the second portion 201b. Therefore, it is possible to suppress the accumulation of air bubbles in the vicinity of the nozzle 21 due to the difference in level, thereby suppressing the occurrence of ejection failure due to the air bubbles.

In the present embodiment, the second portion 201b is formed by narrowing the width in the X direction of the first portion 201a from both sides. can be formed by Here, the first channel 201 in the case of using a silicon single crystal substrate whose surface orientation is preferentially oriented in the (100) plane as the communication plate 15 will be described with reference to FIG. 8 is a cross-sectional view showing a modified example of the first flow path, and is a cross-sectional view according to line BB' of FIG.

As shown in FIG. 8, the communication plate 15 is made of a silicon single crystal substrate whose surface orientation is preferentially oriented to the (110) plane. The first portion 201a and the second portion 201b of the first channel 201 can be formed with high accuracy by anisotropically etching (also referred to as wet etching) the communicating plate 15 using an alkaline solution. .

Here, anisotropic etching is performed using the difference in etching rate of the silicon single crystal substrate. That is, the etching rate of the (111) plane of a silicon single crystal substrate having a surface orientation of the (110) plane is about 1/180 of that of the (110) plane. will be That is, when a silicon single crystal substrate whose surface orientation is preferentially oriented to the (110) plane is immersed in an aqueous potassium hydroxide solution (KOH) or an alkaline solution such as tetramethylammonium hydroxide (TMAH), it is gradually corroded. A first (111) plane perpendicular to the (110) plane and a second plane forming an angle of 70.53 degrees with the first (111) plane and an angle of 37.5 degrees with the (110) plane The (111) plane of appears. By such anisotropic etching, precision processing is performed based on a parallelogram formed by a first (111) plane that is two parallel planes and a second (111) plane that is two parallel planes. It can be performed. In this embodiment, the width of the first portion 201a in the X direction is narrowed from one side so that an acute corner is not formed at the connection portion between the first portion 201a and the second portion 201b of the first flow path 201. Thus, the second portion 201b is formed. That is, the second portion 201b is not formed so as to overlap the first portion 201a when viewed from the X direction. As a result, an obtuse corner is formed at the connecting portion between the first portion 201a and the second portion 201b, and the bubble 210 is prevented from being caught in the corner between the first portion 201a and the second portion 201b. can be suppressed, the air bubbles 210 can be prevented from remaining in the first portion 201a, and the air bubble dischargeability can be improved. On the other hand, for example, as shown in FIG. 9, when an acute-angled corner is formed at the connecting portion between the first portion 201a and the second portion 201b, the air bubble 210 extends from the first portion 201a at an acute angle. It becomes difficult to move to the second portion 201b across the corner. Therefore, the air bubbles 210 remain in the vicinity of the nozzle 21, and the air bubbles 210 may cause ejection failure of the ink droplets.

(Embodiment 3)
FIG. 10 is a plan view of an ink jet recording head, which is an example of a recording head according to Embodiment 3 of the present invention. 11 is a cross-sectional view taken along the line CC' of FIG. 10. FIG. 12 is a cross-sectional view taken along line DD' of FIG. FIG. 13 is a diagram schematically showing a flow path configuration according to Embodiment 3. FIG. In addition, the same code|symbol is attached|subjected to the member similar to embodiment mentioned above, and the overlapping description is abbreviate|omitted.

As shown in FIGS. 11 and 12, a first common liquid chamber 101 and a second common liquid chamber 101 and a second A common liquid chamber 102 and a plurality of individual flow paths 200 for flowing ink from the first common liquid chamber 101 to the second common liquid chamber 102 are provided.

Two rows in which the pressure chambers 12 are arranged side by side in the X direction are provided in the flow path forming substrate 10 in the Y direction. Among the two rows of pressure chambers 12, one row of pressure chambers 12 is referred to as a first pressure chamber 12A, and the other row of pressure chambers 12 is referred to as a second pressure chamber 12B. The first pressure chamber 12A and the second pressure chamber 12B are arranged at positions that do not overlap each other in a plan view from the X direction. Also, the first pressure chambers 12A and the second pressure chambers 12B are arranged in a so-called zigzag arrangement that is shifted in the X direction. In this embodiment, the row in which the first pressure chambers 12A are arranged side by side in the X direction and the row in which the second pressure chambers 12B are arranged side by side in the X direction are arranged at positions shifted by half a pitch in the X direction. ing. Note that a portion of the first pressure chamber 12A and a portion of the second pressure chamber 12B may be arranged at positions that overlap each other in plan view from the first direction X.

Further, in this embodiment, the nozzle 21 communicating with the first pressure chamber 12A is referred to as the first nozzle 21A, and the nozzle 21 communicating with the second pressure chamber 12B is referred to as the second nozzle 21B. In this embodiment, as shown in FIG. 10, in the nozzle row 22, the first nozzles 21A and the second nozzles 21B are alternately arranged in the X direction. Further, in this embodiment, the first nozzle 21A and the second nozzle 21B are arranged at the same position in the Y direction. That is, the nozzles 21 are arranged on a straight line along the X direction. Note that the first nozzle 21A and the second nozzle 21B may be arranged so as not to be at the same position in the second direction Y. In other words, two nozzle rows may be provided: one nozzle row in which the first nozzles 21A are arranged side by side, and another nozzle row in which the second nozzles 21B are arranged side by side.

11 and 12, the communication plate 15 has a first communication portion 16 forming the first common liquid chamber 101 and a fourth communication portion 19 forming the second common liquid chamber 102. is provided.

The first communication portion 16 is the same as that of the first embodiment described above, so redundant description will be omitted.

The fourth communicating portion 19 is provided at a position overlapping the second liquid chamber portion 42 of the case member 40 in the Z direction, and is open to both the +Z side surface and the -Z side surface of the communicating plate 15. That is, it is provided so as to pass through the communication plate 15 in the Z direction. The fourth communicating portion 19 constitutes the second common liquid chamber 102 by communicating with the second liquid chamber portion 42 on the -Z side. That is, the second common liquid chamber 102 is composed of the second liquid chamber portion 42 of the case member 40 and the fourth communication portion 19 of the communication plate 15 . Further, the fourth communication portion 19 extends in the Y direction to a position overlapping the second pressure chamber 12B in the +Z direction in the Z direction.

A compliance substrate 49 is provided on the +Z side opening surface of the second common liquid chamber 102 , and a portion of the wall surface of the second common liquid chamber 102 serves as a compliance portion 494 . In this embodiment, the compliance portion 494 provided in the first common liquid chamber 101 is called a first compliance portion 494A, and the compliance portion 494 provided in the second common liquid chamber 102 is called a second compliance portion 494B. By providing the compliance portion 494 on a part of the wall surface of each of the first common liquid chamber 101 and the second common liquid chamber 102 in this manner, the ink in the first common liquid chamber 101 and the second common liquid chamber 102 is Pressure fluctuations can be absorbed by deformation of the compliance portion 494 .

Incidentally, when only the first compliance section 494A is provided without providing the second compliance section 494B, the pressure fluctuation when ink droplets are ejected in the individual flow path provided with the pressure chamber 12 and the nozzle 21 is the second The ejection characteristics of the ink droplets that are transmitted to the other individual channels via the common liquid chamber 102 and ejected from the other individual channels are not stable, and the ejection characteristics of the ink droplets that are ejected from the plurality of nozzles 21 vary. There is a risk that it will occur. Similarly, when only the second compliance portion 494B is provided without providing the first compliance portion 494A, pressure fluctuations in the individual flow paths are transmitted through the first common liquid chamber 101, and the ink droplet ejection characteristics vary. There is a risk that it will occur. In the present embodiment, both the first common liquid chamber 101 and the second common liquid chamber 102 are provided with compliance portions, so that pressure fluctuations in the individual flow paths are transmitted through the first common liquid chamber 101 and the second common liquid chamber 102 Therefore, it is possible to suppress the occurrence of variations in the ejection characteristics of ink droplets.

Further, when only the first compliance portion 494A is provided without providing the second compliance portion 494B, when ink droplets are ejected from a small number of nozzles 21, the deformation of the first compliance portion 494A causes the ink droplets to flow into the pressure chamber 12. However, when ink droplets are simultaneously ejected from a large number of nozzles 21, the deformation of the first compliance portion 494A alone does not sufficiently supply the ink to the pressure chamber 12, and the ink is ejected at the same time. Depending on the number of nozzles 21, the ejection characteristics of ink droplets, particularly the weight of ink droplets, may vary. In this embodiment, by providing both the first compliance section 494A and the second compliance section 494B, it is possible to suppress the shortage of ink supply to the pressure chamber 12 due to the number of nozzles 21 that simultaneously eject ink droplets. Therefore, it is possible to suppress the occurrence of variations in the ejection characteristics of the ink droplets.

In addition, when the compliance portion 494 is provided in both the first common liquid chamber 101 and the second common liquid chamber 102 in this way, in the present embodiment, the nozzle 21 is positioned between the first common liquid chamber 101 and the second common liquid chamber 102. Since the nozzle plate 20 and the compliance portion 494 are provided so as to open on the Z2 side, the nozzle plate 20 and the compliance portion 494 are arranged in the same direction with respect to the individual flow paths 200 having the pressure chambers 12 and the nozzles 21 in the Z direction, which is the direction perpendicular to the nozzle surface 20a. It is arranged on the Z2 side, which is the side. In this way, by arranging the compliance portion 494 on the same side as the nozzle 21 with respect to the individual channel 200, the compliance portion 494 can be provided in a region where the nozzle 21 is not provided, and the compliance portion 494 can be relatively It can be provided over a large area. Further, by arranging the compliance portion 494 and the nozzle 21 on the same side with respect to the individual channel 200, the compliance portion 494 is arranged at a position close to the individual channel 200, and the pressure of the ink in the individual channel 200 is reduced. Fluctuations can be effectively absorbed by the compliance section 494 .

The position of the compliance portion 494 is not particularly limited to this, and may be arranged on the side opposite to the nozzle 21 with respect to the individual channel 200 in the Z direction. That is, it is possible to provide the compliance portion 494 on the Z1 side surface of the case member 40, the side surface of the case member 40 and the communication plate 15, or the like. However, as described above, arranging the compliance portion 494 on the Z2 side, which is the same as the nozzle 21, places the compliance portion 494 at a position closer to the individual flow path 200 so that the ink pressure fluctuation in the individual flow path 200 can be suppressed. The compliance portion 494 can be effectively absorbed, and the compliance portion 494 can be formed with a relatively large area.

Also, the two compliance sections 494 of this embodiment are provided on one compliance board 49 as shown in FIG. Of course, the compliance board 49 is not limited to this, and an independent compliance board 49 may be provided for each compliance section 494 .

In addition, the individual channel 200 of this embodiment includes a first individual channel 200A having a first nozzle 21A and a second individual channel 200B having a second nozzle 21B. The first individual channels 200A and the second individual channels 200B are alternately arranged in the X direction.

Here, as shown in FIG. 11, the first individual channel 200A includes a first nozzle 21A, a first pressure chamber 12A, a first channel 201A, a second channel 202A, a first supply channel 203A, and a fourth stream. It comprises a channel 204A and a fifth channel 205A.

The first supply path 203A communicates between the first pressure chamber 12A and the first common liquid chamber 101, and extends through the first communication plate 151 in the Z direction, that is, along the Z direction. ing.

The first pressure chamber 12A constitutes a third flow path extending in a direction other than the Z direction. The third flow path of the first individual flow path 200A of this embodiment is composed only of the first pressure chamber 12A. The first pressure chamber 12A is provided in the channel forming substrate 10 as described above. Also, the first pressure chamber 12A is formed with a first resolution in the X direction, which is the direction in which the flow paths are arranged. Since the first pressure chamber 12A and the second pressure chamber 12B are arranged at different positions in the Y direction, the first resolution is the resolution of each of the first pressure chamber 12A and the second pressure chamber 12B. It's about. The first resolution is the pitch of the channels in the X direction, which is the direction in which the channels are arranged.

201 A of 1st flow paths are extended in the Y direction which is a 1st direction between the nozzle plate 20 and the communication plate 15 similarly to Embodiment 1 mentioned above. 201 A of 1st flow paths of this embodiment are formed by providing the recessed part in the 2nd communicating plate 152, and covering the opening of this recessed part with the nozzle plate 20. As shown in FIG. Note that the first flow path 201A is not particularly limited to this, and the nozzle plate 20 may be provided with a recess, and the recess of the nozzle plate 20 may be covered by the second communication plate 152. You may make it provide a recessed part in both nozzle plate 20. FIG.

And the 1st nozzle 21A is arrange|positioned so that it may connect in the middle of 201 A of 1st flow paths.

In addition, the first flow path 201A has a first portion 201a having a first cross-sectional area on the second flow path 202 side of the first nozzle 21A, and a first portion 201a on the second common liquid chamber 102 side of the first nozzle 21A. and a second portion 201b having a second cross-sectional area smaller than the first cross-sectional area. In this embodiment, the first portion 201a is formed by narrowing the height in the Z direction with respect to the second portion 201b, as in the first embodiment described above. Of course, the first portion 201a is not limited to this, and the first portion 201a may be formed by narrowing the width in the X direction of the second portion 201b as in the second embodiment.

202 A of 2nd flow paths are connected with 201 A of 1st flow paths similarly to Embodiment 1 mentioned above, 2nd directions other than the Y direction which is the 1st direction in which 201 A of 1st flow paths were extended , in this embodiment, extends in the Z direction. The second flow path 202B is provided through the communication plate 15 in the Z direction, communicates with the first pressure chamber 12A at one end in the Z direction, and communicates with the first flow path 201A at the other end in the Z direction. are provided.

The fourth channel 204A is provided to penetrate the second communicating plate 152 in the third direction so that one end communicates with the first channel 201A and the other end communicates with the fifth channel 205A. there is That is, the fourth channel 204B extends in the Z direction different from the Y direction, which is the first direction in which the first channel 201A extends.

The fifth flow path 205A is provided between the first communication plate 151 and the second communication plate 152 so that one end communicates with the fourth flow path 204A and the other end communicates with the second common liquid chamber . It extends along the Y direction in the in-plane direction of 20a. The fifth flow path 205A of this embodiment is formed by providing a recess in the second communication plate 152 and covering the recess with the first communication plate 151 . Of course, the fifth flow path 205A may be formed by providing a recess in the first communicating plate 151 and covering it with the second communicating plate 152, and both the first communicating plate 151 and the second communicating plate 152 may be You may make it provide a recessed part in.

In this manner, the first individual flow path 200A includes the first supply path 203A, first pressure chamber 12A, It has a second channel 202, a first channel 201A, a first nozzle 21A, a fourth channel 204A and a fifth channel 205A. That is, in this embodiment, as shown in FIG. 13, the first individual flow path 200A is arranged from the upstream side to the downstream side with respect to the ink flow from the first common liquid chamber 101 to the second common liquid chamber 102. The first pressure chamber 12A and the first nozzle 21A are arranged in this order.

In the first individual channel 200A, ink flows from the first common liquid chamber 101 to the second common liquid chamber 102 through the first individual channel 200A. In addition, by driving the piezoelectric actuator 300, the pressure of the ink in the first pressure chamber 12A is changed, and the pressure of the ink in the first nozzle 21A is increased. Dispensed. When the ink flows from the first common liquid chamber 101 through the first individual channel 200A to the second common liquid chamber 102, the piezoelectric actuator 300 may be driven, or the first common liquid chamber 101 may flow into the first individual channel. Piezoelectric actuator 300 may be driven when ink does not flow through 200A to second common liquid chamber 102 . Ink may temporarily flow from the second common liquid chamber 102 to the first common liquid chamber 101 due to a pressure change caused by driving the piezoelectric actuator 300 .

In the present embodiment, in the first individual channel 200A, the upstream side of the first nozzle 21A, that is, the second channel 202A side of the first nozzle 21A of the first channel 201A and the second channel 202A The channel 202A, the first pressure chamber 12A, and the first supply channel 203A are called a first upstream channel. Further, in the first individual channel 200A, the downstream side of the first nozzle 21A, that is, the fourth channel 204A side of the first nozzle 21A of the first channel 201A, the fourth channel 204A, and the 5 channel 205A is called a first downstream channel.

As shown in FIG. 12, the second individual channel 200B includes a second nozzle 21B, a second pressure chamber 12B, a first channel 201B, a second channel 202B, a second supply channel 203B, and a fourth channel 204B. and a fifth channel 205B.

The second supply path 203B communicates the second pressure chamber 12B and the second common liquid chamber 102, and passes through the first communication plate 151 along the Z direction. is extended along the

The second pressure chamber 12B constitutes a third flow path extending in a direction other than the Z direction. The third flow path of the second individual flow path 200B of this embodiment is composed only of the second pressure chamber 12B. The second pressure chamber 12B is provided in the channel forming substrate 10 as described above. Further, the second pressure chamber 12B is arranged at a position different in the Y direction from the first pressure chamber 12A of the first individual channel 200A, and when viewed from the X direction, the first pressure chamber 12A and the first pressure chamber 12B The two pressure chambers 12B are provided at positions that do not overlap each other. Such a second pressure chamber 12B is formed with a first resolution in the X direction like the first pressure chamber 12A.

In addition, the second pressure chamber 12B and the fifth channel 205A of the first individual channel 200A are arranged at different positions in the Z direction, which is the direction perpendicular to the nozzle surface 20a. Specifically, the second pressure chamber 12B is provided on the −Z side of the first communication plate 151, the fifth flow path 205A is provided on the +Z side of the first communication plate 151, and the second pressure chamber 12B is provided on the +Z side of the first communication plate 151. 12B and the fifth channel 205A are arranged at different positions in the Z direction. Therefore, even if the second pressure chamber 12B and the fifth flow path 205B are arranged close to each other in the X direction, the second pressure chamber 12B and the fifth flow path 205A are arranged at different positions in the Z direction. Therefore, it is necessary to suppress the thickness of the partition separating the second pressure chamber 12B from being thinned, thereby suppressing the variation in ejection characteristics caused by the deformation of the partition of the second pressure chamber 12B and pressure absorption. can be done. Further, even if the second pressure chamber 12B and the fifth flow path 205B are arranged so that at least a part thereof overlaps when viewed in plan from the Z direction, the second pressure chamber 12B and the fifth flow path 205B can communicate with each other. There is no

The first flow path 201B extends in the Y direction, which is the first direction, between the nozzle plate 20 and the communication plate 15, as in the first embodiment described above. The first flow path 201B of this embodiment is formed by providing a recess in the second communication plate 152 and covering the opening of the recess with the nozzle plate 20 . Note that the first flow path 201B is not particularly limited to this, and a recess may be provided in the nozzle plate 20, and the recess of the nozzle plate 20 may be covered with the second communication plate 152. You may make it provide a recessed part in both nozzle plate 20. FIG.

Between the communication plate 15 and the nozzle plate 20, the first flow paths 201A of the first individual flow paths 200A and the first flow paths 201B of the second individual flow paths 200B are alternately arranged in the X direction. there is A resolution in which the first flow paths 201A and 201B are alternately arranged in the X direction is called a second resolution. The second resolution of the first flow paths 201A and 201B is greater than the first resolution of the first pressure chamber 12A or the second pressure chamber 12B. For example, if the first pressure chamber 12A is formed with a first resolution of 300 dpi and the second pressure chamber 12B is formed with a first resolution of 300 dpi, the first flow paths 201A and 201B are formed with a second resolution of 600 dpi. become. Therefore, the first resolution of each of the first pressure chamber 12A and the second pressure chamber 12B is made smaller than the second resolution of the first flow paths 201A and 201B, and the first pressure chamber 12A and the second pressure chamber The opening width of 12B in the X direction can be widened, and the displacement volume of the pressure chamber 12 can be increased.

A second nozzle 21B is arranged in the middle of such a first flow path 201B so as to communicate therewith. In this embodiment, the second nozzle 21B is arranged at the same position as the first nozzle 21A in the Y direction, that is, at a position where the first nozzle 21A and the second nozzle 21B overlap each other when viewed from the X direction. there is

In addition, in the present embodiment, the first flow path 201B includes a third portion 201d having a first cross-sectional area on the second flow path 202 side of the second nozzle 21B, and a second common liquid flow path of the second nozzle 21B. A fourth portion 201e having a second cross-sectional area smaller than the first cross-sectional area is provided on the chamber 102 side.

The fourth portion 201e, like the second portion 201b, is formed by narrowing the height of the third portion 201d in the Z direction, specifically, the ceiling on the side opposite to the nozzle 21. As shown in FIG.

The second flow path 202B is connected to the first flow path 201B in the same manner as in the first embodiment described above, and is connected to the first flow path 201B in a second direction other than the Y direction, which is the first direction in which the first flow path 201B extends. , in this embodiment, extends in the Z direction. The second flow path 202B is provided through the communication plate 15 in the Z direction, communicates with the second pressure chamber 12B at one end in the Z direction, and communicates with the first flow path 201B at the other end in the Z direction. are provided.

The fourth channel 204B is provided to penetrate the second communicating plate 152 in the third direction so that one end communicates with the first channel 201B and the other end communicates with the fifth channel 205B. there is That is, the fourth channel 204B extends in the Z direction different from the Y direction, which is the first direction in which the first channel 201B extends.

The fifth flow path 205B is arranged between the first communication plate 151 and the second communication plate 152 so that one end communicates with the fourth flow path 204B and the other end communicates with the second common liquid chamber 102. It extends along the Y direction in the in-plane direction of 20a. The fifth flow path 205</b>B of the present embodiment is formed by providing a recess in the second communication plate 152 and covering the recess with the first communication plate 151 . Of course, the fifth flow path 205B may be formed by providing a recess in the first communicating plate 151 and covering it with the second communicating plate 152, and both the first communicating plate 151 and the second communicating plate 152 may be You may make it provide a recessed part in.

The fifth channel 205B of the second individual channel 200B and the first pressure chamber 12A of the first individual channel 200A are arranged at different positions in the Z direction, which is the direction perpendicular to the nozzle surface 20a. Specifically, the first pressure chamber 12A is provided on the −Z side of the first communication plate 151, and the fifth flow path 205B is provided on the +Z side of the first communication plate 151. 12A and the fifth channel 205B are arranged at different positions in the Z direction. Therefore, even if the first pressure chamber 12A and the fifth flow path 205B are arranged close to each other in the X direction, the first pressure chamber 12A and the fifth flow path 205B are arranged at different positions in the Z direction. Therefore, the thinning of the partition wall separating the first pressure chambers 12A is suppressed, and the absorption of the pressure of the ink in the first pressure chamber 12A due to the deformation of the partition wall of the first pressure chamber 12A is suppressed. In this way, it is possible to suppress variations in ejection characteristics. In addition, even if the first pressure chamber 12A and the fifth flow path 205B are arranged so that at least a part thereof overlaps in plan view from the Z direction, the first pressure chamber 12A and the fifth flow path 205B are arranged in the Z direction. Since they are arranged at different positions, the first pressure chamber 12A and the fifth flow path 205B do not communicate with each other.

In this way, the second individual flow path 200B is arranged in order from the upstream side communicating with the first common liquid chamber 101 to the downstream side communicating with the second common liquid chamber 102. The fifth flow path 205B, the fourth flow path 204B, It comprises a first channel 201B, a second nozzle 21B, a second channel 202B, a second pressure chamber 12B, and a second supply channel 203B. That is, in this embodiment, as shown in FIG. 13, the second individual flow path 200B is arranged from the upstream side to the downstream side with respect to the flow of ink from the first common liquid chamber 101 to the second common liquid chamber . The second nozzle 21B and the second pressure chamber 12B are arranged in this order. That is, in the first individual flow path 200A and the second individual flow path 200B, the order of the pressure chambers 12 and the nozzles 21 with respect to the flow of ink from the first common liquid chamber 101 to the second common liquid chamber 102 is different. are arranged as In the present embodiment, each individual flow path 200 is provided with one pressure chamber 12 and one nozzle 21 , so the first individual flow path 200A and the second individual flow path 200B are separated from each other by the pressure chamber 12 and the nozzle 21 . are arranged in reverse order.

In the second individual channel 200B, ink flows from the first common liquid chamber 101 to the second common liquid chamber 102 through the second individual channel 200B. Further, by driving the piezoelectric actuator 300, the pressure of the ink in the second pressure chamber 12B is changed to increase the pressure in the second nozzle 21B, thereby ejecting ink droplets from the second nozzle 21B to the outside. be. When the ink flows from the first common liquid chamber 101 through the second individual channel 200B to the second common liquid chamber 102, the piezoelectric actuator 300 may be driven, or the first common liquid chamber 101 may flow from the first common liquid chamber 101 to the second individual channel. Piezoelectric actuator 300 may be driven when ink does not flow through 200B to second common liquid chamber 102 . Ink may temporarily flow from the second common liquid chamber 102 to the first common liquid chamber 101 due to a pressure change caused by driving the piezoelectric actuator 300 . Incidentally, ejection of ink droplets from the second nozzles 21B is determined by the pressure of the ink inside the second nozzles 21B. The pressure of the ink in the second nozzle 21B is the pressure of the ink flowing from the first common liquid chamber 101 toward the second common liquid chamber 102, that is, the so-called circulation pressure, and the drive of the piezoelectric actuator 300. to the second nozzle 21B.

For example, with respect to the flow of ink from the first common liquid chamber 101 to the second common liquid chamber 102, the ink pressure fluctuation in the second pressure chamber 12B causes the ink to flow from the second pressure chamber 12B toward the second nozzle 21B. may flow back and ink droplets may be ejected from the second nozzle 21B. In this way, the reverse flow of ink from the second pressure chamber 12B toward the second nozzle 21B means that the circulation pressure from the first common liquid chamber 101 to the second common liquid chamber 102 is small. By making the circulation pressure relatively small, the pressure loss in the individual flow paths 200 can be reduced. By reducing the pressure loss in the individual flow paths 200, the difference in pressure loss between the individual flow paths 200 can be reduced. can be reduced.

Further, for example, with respect to the flow of ink from the first common liquid chamber 101 to the second common liquid chamber 102, the pressure fluctuation of the ink in the second pressure chamber 12B causes the ink to flow from the second pressure chamber 12B to the second nozzle 21B. The ink may be ejected from the second nozzle 21B without causing the ink to flow back. In this case, since ink does not flow from the second pressure chamber 12B toward the second nozzle 21B, air bubbles are less likely to flow back from the second pressure chamber 12B toward the second nozzle 21B. Ink droplet ejection failure is less likely to occur.

In the present embodiment, in the second individual channel 200B, the upstream side of the second nozzle 21B, that is, the fourth channel 204B side of the first channel 201B relative to the second nozzle 21B, and the fourth channel 204B Channel 204B and fifth channel 205B are referred to as a second upstream channel. Further, in the second individual channel 200B, the downstream side of the second nozzle 21B, that is, the second channel 202B side of the second nozzle 21B of the first channel 201B, the second channel 202B, and the The two pressure chambers 12B and the second supply channel 203B are called a second downstream channel.

Such first individual flow paths 200A and second individual flow paths 200B are alternately arranged in the X direction as shown in FIG. That is, with respect to the flow of ink from the first common liquid chamber 101 to the second common liquid chamber 102 , regardless of the positions of the pressure chambers 12 and the nozzles 21 , the pressure fluctuations in the pressure chambers 12 cause the ink droplets to be ejected from the nozzles 21 . can be discharged. That is, even if the first pressure chamber 12A is arranged upstream and the first nozzle 21A is arranged downstream like the first individual channel 200A, the second nozzle 21B is arranged upstream like the second individual channel 200B. Even if the second pressure chamber 12B is arranged downstream, ink droplets can be selectively ejected from both the first nozzle 21A and the second nozzle 21B by the pressure fluctuation of the ink inside the pressure chamber 12B. Therefore, as described above, with respect to the flow of ink from the first common liquid chamber 101 to the second common liquid chamber 102, the first individual flow path 200A and the second individual flow path 200A in which the order of the pressure chambers 12 and the nozzles 21 are different. By alternately arranging the channels 200B in the X direction, the positions of the pressure chambers 12 are changed between the first individual channels 200A and the second individual channels 200B, that is, the first pressure chambers 12A and the second pressure chambers 12A and 200B are arranged alternately. 12B can be arranged at different positions in the Y direction. Therefore, the pressure chambers 12 of each individual channel 200 can be widened in the X direction, and the pressure chambers 12 can be arranged in the X direction at high density. That is, by arranging the first pressure chamber 12A and the second pressure chamber 12B at different positions in the Y direction, it is possible to thicken the partition between the first pressure chambers 12A arranged side by side in the X direction. The partition walls of the second pressure chambers 12B arranged side by side in the X direction can be thickened. Therefore, even if the first pressure chamber 12A and the second pressure chamber 12B are formed wide in the X direction, it is possible to suppress a decrease in the rigidity of the partition walls, thereby improving the displacement volume and improving the ejection characteristics of the ink droplets. That is, it is possible to increase the weight of the ink droplets, and to suppress the occurrence of crosstalk due to the reduction in the rigidity of the partition walls. Further, even if the first pressure chambers 12A and the second pressure chambers 12B are arranged at high density in the X direction, it is possible to suppress the decrease in the rigidity of the partition walls, and the cross-sectional area caused by the decrease in the rigidity of the partition walls can be suppressed. It is possible to suppress the occurrence of talk.

Incidentally, for example, when only the first individual flow paths 200A are arranged side by side in the X direction without providing the second individual flow paths 200B, if the first pressure chambers 12A are densely arranged in the X direction, the adjacent first pressure chambers 12A The thickness of the partition between the pressure chambers 12A becomes thin, and the rigidity of the partition decreases. When the rigidity of the partition wall is lowered in this manner, crosstalk occurs due to deformation of the partition wall. That is, when ink droplets are simultaneously ejected from the nozzles 21 on both sides of the nozzles 21 for ejecting ink droplets, pressure is applied to the partition wall between the adjacent first pressure chambers 12A from both sides at the same timing. In this case, pressure is applied to the partition wall from both sides regardless of the rigidity of the partition wall, so that the partition wall is difficult to deform. On the other hand, when ink droplets are not ejected from the nozzles 21 on both sides of the nozzles 21 that eject ink droplets, pressure is applied to only one side of the partition wall between the adjacent first pressure chambers 12A. At this time, if the rigidity of the partition wall is low, the partition wall deforms and absorbs pressure fluctuations, thereby deteriorating the ejection characteristics of ink droplets. Therefore, the ejection characteristics of the ink droplets vary due to the difference in the conditions for ejecting the ink droplets from any of the plurality of nozzles 21 . Therefore, when only the first pressure chambers 12A are provided, the first pressure chambers 12A cannot be formed wide in the X direction, and the first pressure chambers 12A cannot be arranged in the X direction at high density. can't

In this embodiment, since the first pressure chamber 12A and the second pressure chamber 12B are arranged at different positions in the Y direction, the thickness of the partition between the first pressure chambers 12A adjacent in the X direction is compared. In addition, the thickness of the partition between the second pressure chambers 12B adjacent in the X direction can be made relatively thick. Therefore, even if the first pressure chamber 12A and the second pressure chamber 12B are formed wide in the X direction, the rigidity of the partition between the first pressure chamber 12A and the partition between the second pressure chamber 12B is reduced. can be suppressed. Therefore, the volume of the first pressure chamber 12A and the second pressure chamber 12B can be increased by suppressing an increase in the size of the flow path substrate in the X direction, and the displacement volume by driving the piezoelectric actuator 300 can be increased. In addition, it is possible to improve the ejection characteristics of the ink droplets, particularly the weight of the ink droplets, and to suppress the occurrence of crosstalk due to the reduction in the rigidity of the partition walls.

Also, even if the distance between the first pressure chamber 12A and the second pressure chamber 12B is shortened in the X direction, the rigidity of the partition between the first pressure chamber 12A and the partition between the second pressure chamber 12B is reduced. can be suppressed, the first pressure chambers 12A and the second pressure chambers 12B can be densely arranged in the X direction. Therefore, it is possible to reduce the size of the flow path substrate in the X direction and improve the discharge volume of the pressure chambers 12 to improve ink droplet ejection characteristics. It is possible to arrange them at a high density and suppress the occurrence of crosstalk due to a decrease in the rigidity of the partition walls.

In addition, since the second resolution of the first flow paths 201A and 201B can be made smaller than the first resolution of the first pressure chamber 12A or the second pressure chamber 12B, the first nozzle 21A and the second nozzle 21B can be placed close to each other. That is, by arranging the nozzle 21 at a position communicating with the first flow passages 201A and 201B extending in the in-plane direction of the nozzle surface 20a, the first pressure chamber 12A and the second pressure chamber 12B are arranged in the Y direction. Since the position of the nozzles 21 can be easily adjusted in the Y direction even if they are arranged at different positions in the direction, the plurality of nozzles 21 can be arranged close to each other in the Y direction, and the plurality of nozzles 21 can be arranged in the X direction. They can be easily arranged in a row on a straight line along the direction.

In such a configuration, two individual flow paths adjacent in the X direction, that is, the first individual flow path 200A and the second individual flow path 200B, when viewed from above in the X direction in which the nozzles 21 are arranged side by side. , the interval between the nozzles 21, that is, the interval between the first nozzle 21A and the second nozzle 21B, is smaller than the interval between the pressure chambers 12, that is, the interval between the first pressure chamber 12A and the second pressure chamber 12B. .

In this way, by making the distance between the first nozzle 21A and the second nozzle 21B smaller than the distance between the first pressure chamber 12A and the second pressure chamber 12B in the Y direction, the plurality of nozzles 21 are brought closer to each other. The first pressure chambers 12A and the second pressure chambers 12B can be arranged at high density, and the first pressure chambers 12A and the second pressure chambers 12B can be arranged at separate positions in the Y direction. , can be arranged at a lower density than the nozzles 21 . Therefore, it is possible to increase the excluded volume of each pressure chamber 12 and to reduce the size of the flow path substrate by arranging the pressure chambers 12 at high density.

In addition, by arranging the plurality of nozzles 21 at the same position in the Y direction, there is no need to adjust the timing of ejecting ink droplets from each nozzle 21 so as to be shifted, and drive control of the piezoelectric actuator 300 can be simplified. can. Incidentally, when ink droplets are ejected by moving the recording head 1 in the Y direction, if ink droplets are ejected at the same timing from the nozzles 21 arranged at different positions in the Y direction, the ink droplets on the ejected medium will not be ejected. This is because the landing position shifts in the Y direction, so it is necessary to adjust the driving timing of the piezoelectric actuator 300 so that the ink droplets land in the same position in the Y direction.

Further, if the first nozzle 21A and the second nozzle 21B are arranged at relatively separated positions in the Y direction, turbulent flow generated by the ink droplets ejected from the first nozzle 21A and the second nozzle 21B, respectively. may affect each other, causing a deviation in the flight direction of the ink droplets. By arranging the first nozzles 21A and the second nozzles 21B relatively close to each other as in the present embodiment, the influence of turbulent flow of ink droplets ejected from each other's nozzles 21 is suppressed, and the ink droplets It is possible to suppress the variation in the flight direction of the ink droplets, and suppress the displacement of the landing positions of the ink droplets on the ejection receiving medium.

Moreover, in the present embodiment, the first nozzle 21A and the second nozzle 21B are arranged on a straight line along the X direction, but the present invention is not particularly limited to this. For example, if the first nozzle 21A and the second nozzle 21B are communicated in the middle of the first flow paths 201A and 201B, respectively, the first nozzle 21A and the second nozzle 21B are arranged at positions shifted from each other in the Y direction. may have been

As described above, the ink jet recording head 1, which is an example of the liquid jet head of the present embodiment, includes the nozzle plate 20, the channel substrate in which the channels are formed, and the pressure applied to the ink, which is the liquid in the channels. and a piezoelectric actuator 300 that is an energy generating element that generates a change. and a plurality of individual channels 200 through which ink flows from the first common liquid chamber 101 toward the second common liquid chamber 102 in communication with the nozzles 21 communicating with the outside, and the nozzles 21 is disposed in the middle and extends in the Y direction, which is the first direction that is the in-plane direction of the nozzle surface 20a of the nozzle plate 20 where the nozzles 21 open, and the first flow path 201 and a second flow path 202 connected to and extending in the Z direction, which is a second direction other than the Y direction, and a second flow path 202 connected to and extending in the Y direction, which is a third direction other than the Z direction. and a pressure chamber 12 that is arranged in the third flow path and causes a pressure change due to a piezoelectric actuator 300. A first portion 201a having a cross-sectional area of 1 and a second cross-sectional area having a smaller cross-sectional area than the first cross-sectional area are provided on the opposite side of the nozzle 21 from the second flow path 202. two portions 201b;

In this way, by connecting the nozzle 21 in the middle of the first flow path 201 extending in the Y direction, the ink that has increased in viscosity due to being dried by the nozzle 21 is moved downstream by the ink flowing through the first flow path 201 . can flow into the second common liquid chamber 102 on the side. Therefore, the nozzles 21 can be arranged away from the corners of the second flow passages 202 and the nozzle plate 20 where ink is stagnant, and the ink thickened by the nozzles 21 can flow through the second flow passages 202 and the nozzle plate. 20, clogging of the nozzles 21 due to thickened ink or air bubbles, and clogging of the nozzles 21. can be suppressed. In addition, it is possible to prevent the air bubbles entering from the nozzle 21 from staying at the corner between the second channel 202 and the nozzle plate 20, and prevent the air bubbles entering from the nozzle 21 from moving to the pressure chamber 12 side. can be suppressed, and ejection failure of ink droplets can be suppressed.

In addition, by providing the first portion 201a, which is the first cross-sectional area on the second flow path side of the nozzle 21, the pressure loss from the pressure chamber 12 to the nozzle 21 is reduced, and the ink droplet ejected from the nozzle 21 is reduced. weight reduction can be suppressed.

Furthermore, by providing the second portion 201b having the second cross-sectional area closer to the second common liquid chamber 102 than the nozzles 21, the flow velocity of the ink flowing through the second portion 201b can be increased. The viscous ink and air bubbles entering from the nozzle 21 can be removed by the ink flowing through the second portion 201b at a relatively high speed, and the thickened ink and air bubbles are less likely to flow back upstream.

In addition, in the recording head 1 of the present embodiment, among the individual channels 200, the three individual channels 200 adjacent in the X direction, which is the direction in which the nozzles 21 are arranged, are the first common liquid chamber 101 and the second common liquid chamber 101, respectively. The first individual flow path 200A and the second individual flow path 200B, which communicate with the liquid chamber 102 and are adjacent in the X direction, are arranged in the direction in which ink, which is the liquid, flows from the first common liquid chamber 101 to the second common liquid chamber 102. , the arrangement order of the pressure chambers 12 and the nozzles 21 is different.

In this way, by arranging the first individual channel 200A and the second individual channel 200B, which are the individual channels 200 in which the pressure chambers 12 and the nozzles 21 are arranged in different orders, so as to be adjacent to each other in the X direction, The pressure chambers 12 of the individual channels 200 can be arranged at different positions in the Y direction. Therefore, compared to the case where the pressure chambers 12 and the nozzles 21 are arranged in parallel with the individual flow paths 200 in the same order, the width in the direction in which the pressure chambers 12 are arranged in parallel is widened, and the displacement volume of the pressure chambers 12 by the piezoelectric actuators 300 is reduced. can be increased to increase the ejection weight of ink droplets, and the pressure chambers 12 can be arranged in parallel in the X direction at high density to reduce the size of the flow path substrate. In addition, since the pressure chambers 12 of the adjacent individual flow paths 200 can be arranged at positions shifted in the Y direction, the arrangement density of the pressure chambers 12 of the individual flow paths 200 adjacent in the X direction can be improved and the nozzle 21 can be arranged in high density.

In addition, the individual flow paths 200 are independently communicated with the first common liquid chamber 101 and the second common liquid chamber 102 without joining the individual flow paths 200 in the middle. It is possible to suppress the occurrence of crosstalk due to the influence of pressure fluctuations in the In other words, if the individual flow paths 200 merge before communicating with the first common liquid chamber 101 and the second common liquid chamber 102, the ink pressure change in one of the individual flow paths 200 affects the other individual flow path. 200, resulting in variations in ink ejection characteristics. In this embodiment, the plurality of individual flow paths 200 communicate only with the first common liquid chamber 101 and the second common liquid chamber 102 having relatively large volumes, so that the plurality of individual flow paths 200 communicate with each other. The influence of pressure fluctuations can be reduced, and variations in ink ejection characteristics can be suppressed.

Furthermore, since the first common liquid chamber 101 and the second common liquid chamber 102 communicate with each other only through the individual flow paths 200, the ink flows in the first common liquid chamber 101 in the X direction, which is the direction in which the individual flow paths 200 are arranged. Since the ink does not flow in any direction, pressure differences in the ink supplied to the plurality of individual flow paths 200 are unlikely to occur, and variations in ejection characteristics of the ink ejected from the nozzles 21 are unlikely to occur. Incidentally, when the ink flows through the first common liquid chamber 101 in the X direction, the pressure of the ink supplied to the individual flow channel 200 communicating with the upstream side of the first common liquid chamber 101 is higher than the pressure of the individual flow channel communicating with the downstream side. The pressure of the ink supplied to the channels 200 is lowered, and variations in the pressure of the ink supplied to the individual channels 200 tend to cause variations in the ink ejection characteristics.

In this embodiment, the flow resistance of the upstream flow path on the first common liquid chamber 101 side of the nozzle 21 of the individual flow path 200 is is preferably −50% or more and +50% or less. In this way, the channel resistance from the nozzle 21 to the second common liquid chamber 102 of the individual channel 200 is −50% or more and +50% or less with respect to the channel resistance from the nozzle 21 to the first common liquid chamber 101. As a result, the first individual channel 200A and the second individual channel 200B have a shape that is reversed with respect to the direction in which the ink flows from the first common liquid chamber 101 to the second common liquid chamber 102. In this case, the pressures in the first nozzles 21A and the pressures in the second nozzles 21B can be easily uniformed, thereby suppressing variations in ink droplet ejection characteristics.

Further, the upstream flow path on the first common liquid chamber 101 side of the nozzle 21 of the individual flow path 200 and the downstream flow path on the second common liquid chamber 102 side of the nozzle 21 have the same flow path resistance. more preferably provided. As a result, when the first individual flow path 200A and the second individual flow path 200B are formed in a shape in which the ink flowing direction from the first common liquid chamber 101 to the second common liquid chamber 102 is reversed to each other, , the flow path resistance can be made uniform between the first individual flow path 200A and the second individual flow path 200B, and variations in ink droplet ejection characteristics can be further reduced.

Further, the channel resistances of the upstream channel and the downstream channel of the individual channel 200 are not limited to those described above. For example, the upstream channel and the downstream channel may have different channel resistances. In such a case, different voltages may be applied to the piezoelectric actuators 300 of the individual channels 200 adjacent in the direction in which the nozzles 21 are arranged.

For example, in the case of a structure in which the first individual channel 200A and the second individual channel 200B are inverted, when the channel resistance of the first upstream channel is greater than that of the first downstream channel, the first nozzle 21A The pressure of the ink inside becomes smaller, and the weight of the ink droplet ejected from the first nozzle 21A becomes smaller. On the other hand, in the case of the structure in which the first individual channel 200A and the second individual channel 200B are inverted, the channel resistance of the second upstream channel is smaller than the channel resistance of the second downstream channel. As a result, the ink pressure in the second nozzle 21B becomes smaller. Therefore, the weight of the ink droplet ejected from the second nozzle 21B is increased. Therefore, the voltage applied to the piezoelectric actuators 300 corresponding to the first individual flow paths 200A is set relatively higher than the voltage applied to the piezoelectric actuators 300 corresponding to the second individual flow paths 200B. In order to make the voltage applied to the piezoelectric actuator 300 corresponding to the first individual channel 200A relatively larger than the voltage applied to the piezoelectric actuator 300 corresponding to the second individual channel 200B, for example, the first The voltage applied to the piezoelectric actuator 300 corresponding to the individual channel 200A may be increased, or the voltage applied to the piezoelectric actuator 300 corresponding to the second individual channel 200B may be decreased. Both may be performed with respect to the reference voltage. As a result, even if there is a relatively large difference between the ink pressure in the first nozzle 21A and the ink pressure in the second nozzle 21B, by adjusting the voltage applied to the piezoelectric actuator 300, the first nozzle Print quality can be improved by reducing variations in the weight of ink droplets ejected from the second nozzles 21A and 21B.

(Other embodiments)
Although each embodiment of the present invention has been described above, the basic configuration of the present invention is not limited to the above.

For example, in each of the above-described embodiments, the first communication plate 151 and the second communication plate 152 are laminated in the Z direction as the communication plate 15. However, the number of the communication plate 15 is not limited to this. , or may be formed by laminating three or more substrates.

Further, for example, in each of the above-described embodiments, the configuration in which one first common liquid chamber 101 and one second common liquid chamber 102 are provided in one channel substrate was exemplified, but it is particularly limited to this. not a thing

Here, a modified example of the recording head 1 will be described with reference to FIGS. 14 and 15. FIG. 14 is a schematic cross-sectional view for explaining the configuration of the flow path, and is a schematic cross-sectional view according to line CC' of FIG. FIG. 15 is a schematic cross-sectional view for explaining the configuration of the flow path, and is a schematic cross-sectional view according to line DD' of FIG.

As shown in FIGS. 14 and 15, in the channel substrate 400, the first common liquid chambers 101 and the second common liquid chambers 102 are alternately and repeatedly arranged in the Y direction. Also, a plurality of individual channels 200 are provided for supplying ink from the first common liquid chamber 101 to the second common liquid chamber 102 . A plurality of individual channels 200 are provided along the X direction for one set of one first common liquid chamber 101 and one second common liquid chamber 102 . The individual channel 200 is located between the first common liquid chamber 101 and the second common liquid chamber 102 in the Y direction.

The individual channel 200 has a first individual channel 200A having a first nozzle 21A and a second individual channel 200B having a second nozzle 21B.

As shown in FIG. 14, the first individual channel 200A includes a first nozzle 21A, a first pressure chamber 12A, a first channel 201A, a second channel 202A, and a first supply channel 203A. The 1st nozzle 21A is connected and provided in the middle of 201 A of flow paths.

In this manner, the first individual flow path 200A includes the first supply path 203A, first pressure chamber 12A, It has 202 A of 2nd flow paths, 201 A of 1st flow paths, and 21 A of 1st nozzles. In other words, in the present embodiment, the first individual flow path 200A is arranged in the first pressure chamber 12A from the upstream side to the downstream side with respect to the flow of ink from the first common liquid chamber 101 to the second common liquid chamber 102. and the first nozzle 21A are arranged in this order.

As shown in FIG. 15, the second individual channel 200B includes a second nozzle 21B, a second pressure chamber 12B, a first channel 201B, a second channel 202B, and a second supply channel 203B. The 2nd nozzle 21B is connected and provided in the middle of the flow path 201B.

In this manner, the second individual flow path 200B includes the first flow path 201B, the second nozzle 21B, and the second nozzle 21B in order from the upstream side communicating with the first common liquid chamber 101 to the downstream side communicating with the second common liquid chamber . It comprises two channels 202B and a second supply channel 203B. That is, in the present embodiment, the second individual flow path 200B and the second nozzle 21B move from the upstream side to the downstream side with respect to the flow of ink from the first common liquid chamber 101 to the second common liquid chamber 102. The second pressure chambers 12B are arranged in this order. That is, in the first individual flow path 200A and the second individual flow path 200B, the order of the pressure chambers 12 and the nozzles 21 with respect to the flow of ink from the first common liquid chamber 101 to the second common liquid chamber 102 is different. are arranged as In the present embodiment, each individual flow path 200 is provided with one pressure chamber 12 and one nozzle 21 , so the first individual flow path 200A and the second individual flow path 200B are separated from each other by the pressure chamber 12 and the nozzle 21 . are arranged in reverse order.

In this embodiment, the first nozzles 21A and the second nozzles 21B are arranged on a straight line in the X direction. Incidentally, the first nozzle 21A and the second nozzle 21B do not have to be aligned on a straight line in the X direction. 14 and 15 show only two sets of the first common liquid chamber 101 and the second common liquid chamber 102, but three or more sets may be provided in the Y direction, in a so-called matrix configuration. may be placed in Also, a common flexible cable 120 may be connected to the piezoelectric actuators 300 corresponding to three or more sets of the first common liquid chamber 101 and the second common liquid chamber 102 .

16 and 17 show modifications of the recording head 1 of FIGS. 14 and 15. FIG. 16 is a schematic cross-sectional view for explaining the configuration of the flow path, and is a schematic cross-sectional view according to line CC' of FIG. FIG. 17 is a schematic cross-sectional view for explaining the configuration of the flow path, and is a schematic cross-sectional view according to line DD' of FIG.

As shown in FIGS. 16 and 17, the first common liquid chambers 101 and the second common liquid chambers 102 are alternately arranged in the Y direction.

Ink is sent from one first common liquid chamber 101 to the second common liquid chambers 102 on both sides in the Y direction by two rows of individual flow paths 200 . Ink is sent to one second common liquid chamber 102 from the first common liquid chambers 101 on both sides in the Y direction by two rows of individual flow paths 200 . That is, the first common liquid chamber 101 communicates with two rows of individual flow channels 200 , and one second common liquid chamber 102 communicates with two rows of individual flow channels 200 . In this manner, by using the first common liquid chamber 101 and the second common liquid chamber 102 for two rows of the individual channels 200, the nozzles 21 are arranged at high density, and the size of the channel substrate 400 can be reduced. can be planned.

Further, in each of the above-described embodiments, the configuration in which the individual flow path 200 is provided between the first common liquid chamber 101 and the second common liquid chamber 102 in the Y direction has been exemplified, but the present invention is not particularly limited to this. Modifications of the recording head 1 will now be described with reference to FIGS. 18 to 20. FIG. 18 is a schematic cross-sectional view for explaining the configuration of the flow path, and is a schematic cross-sectional view according to line CC' of FIG. FIG. 19 is a schematic cross-sectional view for explaining the configuration of the flow path, and is a schematic cross-sectional view according to line DD' of FIG. FIG. 20 is a diagram schematically showing a channel.

As shown in FIGS. 18 and 19, a first common liquid chamber 101 and a second common liquid chamber 102 are arranged side by side in the Y direction. Each nozzle 21 of the individual flow path 200 for sending ink from the first common liquid chamber 101 to the second common liquid chamber 102 is located on the opposite side of the first common liquid chamber 101 to the second common liquid chamber 102 in the Y direction. are placed in

Specifically, the individual channel 200 includes a first individual channel 200A having a first nozzle 21A and a second individual channel 200B having a second nozzle 21B.

As shown in FIG. 18, the first individual channel 200A includes a first nozzle 21A, a first pressure chamber 12A, a first channel 201A, a second channel 202A, and a first supply channel 203A.

The first supply path 203A extends along the Y direction from the first common liquid chamber 101 toward the opposite side of the second common liquid chamber 102 in the Y direction.

The first pressure chamber 12A is arranged on the -Z side of the channel substrate 400. As shown in FIG.

The second flow path 202A extends along the Z direction and communicates between the first pressure chamber 12A and the first flow path 201A.

The first channel 201A extends along the Y direction and communicates the second channel 202A with the second common liquid chamber 102 .

That is, the first individual channel 200A extends from the first common liquid chamber 101 toward the opposite side of the second common liquid chamber 102 in the Y direction and communicates with the second common liquid chamber 102. ing.

In the first individual channel 200A, the first pressure chamber 12A and the first nozzle 21A are arranged in this order with respect to the direction in which the ink flows from the first common liquid chamber 101 to the second common liquid chamber 102. It is

As shown in FIG. 19, the second individual channel 200B includes a second nozzle 21B, a second pressure chamber 12B, a first channel 201B, a second channel 202B, a second supply channel 203B, and a sixth channel 206. Equipped with

The second supply path 203B extends along the Y direction and communicates the second pressure chamber 12B and the second common liquid chamber 102 with each other.

The second pressure chamber 12B is arranged on the −Z side of the channel substrate 400. As shown in FIG. Also, the second pressure chamber 12B is arranged at a different position in the Y direction from the first pressure chamber 12A.

The second flow path 202B extends along the Z direction and communicates the second pressure chamber 12B and the first flow path 201B.

The first channel 201B extends along the Y direction and communicates the second channel 202B and the sixth channel 206 with each other.

The sixth flow path 206 extends along the Z direction and communicates the first flow path 201B and the first common liquid chamber 101 with each other.

That is, the second individual channel 200B extends from the first common liquid chamber 101 toward the opposite side of the second common liquid chamber 102 in the Y direction, and communicates with the second common liquid chamber 102. ing.

In such a second individual channel 200B, the second nozzle 21B and the second pressure chamber 12B are arranged in this order with respect to the direction in which the ink flows from the first common liquid chamber 101 to the second common liquid chamber 102. It is That is, as shown in FIG. 20, in the first individual channel 200A and the second individual channel 200B, the pressure chamber 12 and the pressure chamber 12 correspond to the ink flow from the first common liquid chamber 101 to the second common liquid chamber . They are arranged so that the order with respect to the nozzles 21 is different. In the present embodiment, each individual flow path 200 is provided with one pressure chamber 12 and one nozzle 21 , so the first individual flow path 200A and the second individual flow path 200B are separated from each other by the pressure chamber 12 and the nozzle 21 . are arranged in reverse order.

In such a configuration, the first pressure chamber 12A and the second pressure chamber 12B are separated by changing the order of the pressure chambers 12 and the nozzles 21 between the first individual flow passage 200A and the second individual flow passage 200B. The pressure chambers 12 can be arranged at different positions in the Y direction, and the width in the X direction, which is the direction in which the pressure chambers 12 are arranged side by side, can be increased to increase the displacement volume and to arrange the pressure chambers 12 at high density.

18 and 19, the first nozzle 21A and the second nozzle 21B are arranged on one side of the first common liquid chamber 101 and the second common liquid chamber 102 in the Y direction. However, it can be placed on both sides. That is, the individual flow paths 200 are provided on both sides in the Y direction for one first common liquid chamber 101, and the individual flow paths 200 are provided on both sides in the Y direction for one second common liquid chamber 102. good too.

Further, by connecting the first nozzles 21A and the second nozzles 21B in the middle of the first flow paths 201A and 201B, respectively, the ink thickened by the first nozzles 21A and the second nozzles 21B and the air bubbles that have entered are removed. Ink flowing through the first flow paths 201A and 201B at a high flow rate can flow downstream. Therefore, it is possible to suppress the occurrence of ejection failure due to thickened ink or air bubbles.

Note that the nozzle 21 is not provided between the first common liquid chamber 101 and the second common liquid chamber 102 in plan view from the Z direction, which is the direction perpendicular to the nozzle surface 20a shown in FIGS. 18 and 19 described above. Compared to the configuration, in the configurations in which the nozzles 21 are provided between the first common liquid chamber 101 and the second common liquid chamber 102 in plan view from the Z direction as in each of the above-described embodiments, the individual flow paths 200 can be simplified, and multi-layering of the communication plate 15 can be suppressed.

Further, in each of the above-described embodiments, the configuration in which one nozzle 21 and one pressure chamber 12 are provided in each individual channel 200 is illustrated, but the number of nozzles 21 and pressure chambers 12 is not particularly limited, Two or more nozzles 21 may be provided for one pressure chamber 12 , and two or more pressure chambers 12 may be provided for one nozzle 21 . However, from the nozzles 21 provided in one individual channel 200, ink droplets are simultaneously ejected in one ejection cycle. In other words, even if a plurality of nozzles 21 are provided in one individual channel 200, the plurality of nozzles 21 either eject ink droplets simultaneously or do not eject ink droplets simultaneously. Just do it. That is, in a configuration in which a plurality of nozzles 21 are provided in one individual flow path 200, ejection and non-ejection of ink droplets from the plurality of nozzles 21 may be performed simultaneously.

Further, in each of the above-described embodiments, the flow path substrate includes the flow path forming substrate 10, the communication plate 15, the nozzle plate 20, the compliance substrate 49, the case member 40, etc., but the flow path substrate is particularly limited to this. Instead, the channel substrate may be a single substrate, or a laminate of two or more substrates. For example, the channel substrate may include the channel forming substrate 10 and the nozzle plate 20, and may not include the communication plate 15, the compliance substrate 49, and the case member 40. Further, one pressure chamber 12 may be formed by a plurality of flow path forming substrates 10, or the pressure chambers 12, the first common liquid chamber 101 and the second common liquid chamber 102 may be formed in the flow path forming substrate 10. may

Further, in each of the above-described embodiments, the thin-film type piezoelectric actuator 300 is used as an energy generating element that causes a pressure change in the pressure chamber 12, but the present invention is not limited to this, and for example, a green sheet may be attached. A thick-film type piezoelectric actuator formed by a method such as the above, and a vertical vibration type piezoelectric actuator that alternately laminates a piezoelectric material and an electrode forming material and expands and contracts in the axial direction can be used. Also, as an energy generating element, a heating element is placed in the pressure chamber, and droplets are ejected from a nozzle by bubbles generated by heat generated by the heating element, or static electricity is generated between the diaphragm and the electrode, A so-called electrostatic actuator or the like can be used, which deforms a diaphragm by electrostatic force and discharges liquid droplets from nozzle openings.

Here, an example of an ink jet recording apparatus, which is an example of the liquid ejecting apparatus of this embodiment, will be described with reference to FIG. Note that FIG. 21 is a diagram showing a schematic configuration of the ink jet recording apparatus of the present invention.

As shown in FIG. 21, in an ink jet recording apparatus I, which is an example of a liquid ejecting apparatus, a plurality of recording heads 1 are mounted on a carriage 3 . A carriage 3 on which the recording head 1 is mounted is provided axially movably on a carriage shaft 5 attached to an apparatus main body 4 . In this embodiment, the moving direction of the carriage 3 is the Y direction.

Further, the apparatus main body 4 is provided with a tank 2 which is a storage means in which ink is stored as a liquid. The tank 2 is connected to the recording head 1 via a supply pipe 2a such as a tube, and ink from the tank 2 is supplied to the recording head 1 via the supply pipe 2a. The recording head 1 and the tank 2 are connected via a discharge pipe 2b such as a tube, and the ink discharged from the recording head 1 is returned to the tank 2 via the discharge pipe 2b. will be Note that the tank 2 may be composed of a plurality of tanks.

The driving force of the driving motor 7 is transmitted to the carriage 3 via a plurality of gears (not shown) and a timing belt 7a, so that the carriage 3 on which the recording head 1 is mounted is moved along the carriage shaft 5. FIG. On the other hand, the apparatus main body 4 is provided with a transport roller 8 as transport means, and the transport roller 8 transports a recording sheet S, which is an ejection receiving medium such as paper. The conveying means for conveying the recording sheet S is not limited to the conveying roller 8, and may be a belt, a drum, or the like. In this embodiment, the conveying direction of the recording sheet S is the X direction.

In the above-described ink jet recording apparatus I, the recording head 1 is mounted on the carriage 3 and moves in the main scanning direction, but is not limited to this. The present invention can also be applied to a so-called line-type recording apparatus that prints by simply moving a recording sheet S such as paper in the sub-scanning direction.

In each embodiment, an ink jet recording head is used as an example of a liquid ejecting head, and an ink jet recording apparatus is used as an example of a liquid ejecting apparatus. , and can of course be applied to a liquid ejecting head or a liquid ejecting apparatus that ejects a liquid other than ink. Other liquid jet heads include, for example, various recording heads used in image recording apparatuses such as printers, coloring material jet heads used in manufacturing color filters such as liquid crystal displays, organic EL displays, and FEDs (field emission displays). and an electrode material ejection head used for electrode formation, and a bioorganic material ejection head used for bio-chip manufacturing.

Here, an example of the liquid circulation system of this embodiment will be described with reference to FIG. FIG. 22 is a block diagram for explaining the liquid circulation system of the ink jet recording apparatus, which is the liquid ejecting apparatus of the present invention.

As shown in FIG. 22, the liquid circulation system includes a main tank 500, the print head 1 of each embodiment described above, a first tank 501, a second tank 502, a compressor 503, a vacuum pump 504, and a A first liquid-sending pump 505 and a second liquid-sending pump 506 are provided.

A print head 1 and a compressor 503 are connected to the first tank 501 , and the ink in the first tank 501 is supplied to the print head 1 at a predetermined positive pressure by the compressor 503 .

The second tank 502 is connected to the first tank 501 via a first liquid-sending pump 505 , and the ink in the second tank 502 is sent to the first tank 501 by the first liquid-sending pump 505 .

The second tank 502 is also connected to the printhead 1 and a vacuum pump 504 , and the vacuum pump 504 discharges ink from the printhead 1 to the second tank 502 under a predetermined negative pressure.

That is, ink is supplied from the first tank 501 to the printhead 1 and discharged from the printhead 1 to the second tank 502 . The ink circulates by feeding the ink from the second tank 502 to the first tank 501 by the first liquid feeding pump 505 .

The main tank 500 is connected to the second tank 502 via a second liquid feed pump 506, and the second tank 502 is replenished with the ink consumed by the printhead 1 from the main tank 500. be. Note that the replenishment of ink from the main tank 500 to the second tank 502 may be performed, for example, when the liquid surface of the ink in the second tank 502 becomes lower than a predetermined height.

I... Inkjet recording apparatus (liquid ejecting apparatus), 1... Inkjet recording head (liquid ejecting head), 2... Tank, 2a... Supply pipe, 2b... Discharge pipe, 3... Carriage, 4... Apparatus main body, 5... Carriage Shaft 7 Drive motor 7a Timing belt 8 Conveying roller 10 Flow path forming substrate 12 Pressure chamber 12A First pressure chamber 12B Second pressure chamber 15 Communication plate 151 First communication plate 152 Second communication plate 16 First communication portion 17 Second communication portion 18 Third communication portion 19 Fourth communication portion 20 Nozzle plate 20a Nozzle surface, 21 Nozzle 21a First hole 21b Second hole 21A First nozzle 21B Second nozzle 30 Protective substrate 31 Piezoelectric actuator holding portion 32 Through hole 40 Case member 41 First liquid chamber 42 Second liquid chamber 43 Inlet 44 Outlet 45 Connection port 49 Compliance substrate 50 Diaphragm 60 First electrode 70 Piezoelectric Body layer 80 Second electrode 90 Lead electrode 101 First common liquid chamber 102 Second common liquid chamber 120 Flexible cable 121 Drive circuit 200 Individual channel 200A First Individual channel 200B... Second individual channel 201, 201A, 201B... First channel 201a... First part 201b... Second part 201c... Inclined surface 201d... Third part 201e... Fourth Parts 202, 202A, 202B... Second flow path 203... Supply path 203A... First supply path 203B... Second supply path 204A, 204B... Fourth flow path 205A, 205B... Fifth flow path 206... Sixth channel, 210... Bubble, 300... Piezoelectric actuator (energy generating element), 400... Channel substrate, 491... Sealing film, 492... Fixed substrate, 493... Opening, 494... Compliance part, 494A... First compliance part 494B... Second compliance part 500... Main tank 501... First tank 502... Second tank 503... Compressor 504... Vacuum pump 505... First liquid feeding pump 506... Second Liquid feed pump, S...Recording sheet

Claims (9)

a channel substrate including a nozzle plate and having channels formed thereon;
an energy generating element that causes a pressure change in the liquid in the flow channel,
The flow path is
a first common liquid chamber;
a second common liquid chamber;
a plurality of individual flow paths communicating with the first common liquid chamber and the second common liquid chamber so that liquid flows from the first common liquid chamber toward the second common liquid chamber;
including
The individual channels are
a nozzle communicating with the outside;
a first flow path having the nozzle disposed in the middle thereof and extending in a first direction, which is an in-plane direction of a nozzle surface of the nozzle plate on which the nozzle opens;
a second flow path connected to the first flow path and extending in a second direction other than the first direction;
a third flow path connected to the second flow path and extending in a third direction other than the second direction;
a pressure chamber arranged in the third flow path and causing a pressure change by the energy generating element;
with
The first flow path is
a portion having a first cross-sectional area on the second flow channel side from the nozzle;
a portion having a second cross-sectional area, which is smaller than the first cross-sectional area, on the opposite side of the second flow path from the nozzle;
including
three of the individual channels that are adjacent in the direction in which the nozzles are arranged in parallel communicate with the first common liquid chamber and the second common liquid chamber, respectively;
In the two individual flow paths that are adjacent in the side-by-side direction, the order of arrangement of the pressure chambers and the nozzles is different in the liquid flow direction from the first common liquid chamber to the second common liquid chamber. A liquid jet head characterized by: 2. The liquid jet head according to claim 1, wherein the cross-sectional area of the first flow path is smaller than the cross-sectional area of the second flow path. The portion having the second cross-sectional area is formed with a smaller cross-sectional area than the portion having the first cross-sectional area by narrowing the width in the direction in which the nozzles are arranged side by side with respect to the portion having the first cross-sectional area. 3. The liquid jet head according to claim 1, wherein the liquid jet head is The portion with the second cross-sectional area is narrowed in one width in the side-by-side direction with respect to the portion with the first cross-sectional area so that the portion with the second cross-sectional area and the first cross-sectional area 4. The liquid jet head according to claim 3, wherein no sharp corner is formed in the connecting portion with the portion. The portion having the second cross-sectional area is made higher than the portion having the first cross-sectional area by narrowing the height in the direction perpendicular to the nozzle surface where the nozzle opens. 5. The liquid jet head according to claim 1, wherein the liquid jet head is formed with a small cross-sectional area. The portion with the second cross-sectional area reduces the height of one side opposite to the nozzle in the perpendicular direction with respect to the portion with the first cross-sectional area, and the portion with the first cross-sectional area. 6. The liquid jet head according to claim 5, wherein the height-reduced connection portion with the portion of the second cross-sectional area is an inclined surface inclined with respect to the direction of the normal to the nozzle surface. . 7. The individual channel according to any one of claims 1 to 6, wherein the channel resistance on the downstream side is -50% or more and +50% or less with respect to the channel resistance on the upstream side of the nozzle. 1. The liquid jet head according to Item 1. 8. The method according to any one of claims 1 to 7 , wherein a direction in which the liquid flows in the first channel is the same as a direction in which the liquid flows in the third channel. liquid jet head. A liquid ejecting apparatus comprising the liquid ejecting head according to any one of claims 1 to 8 .

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